Dermatology Revision E6.5 PDF

Dermatology Revision 1 01 1 DERMATOLOGY REVISION 1 ----- Active space ----- Basics in Dermatology...

Dermatology Revision 1 01 1 DERMATOLOGY REVISION 1 ----- Active space ----- Basics in Dermatology 00:00:22 Layers of Skin : Epidermis : S. corneum Flat cells, keratinised, no nucleus. S. lucidum Only in palms & soles. Stratum 1. Keratohyaline granules (profilaggrin +nt). granulosum Profilaggrin gets converted to Filaggrin Filaggrin involved in in Atopic dermatitis & Ichthiosis vulgaris 2. Lamellar granules/ Odland bodies (acts as barrier) S. spinosum Desmosomes (with prominent spines) present. Antibodies to desomosomes seen in Pemphigus disorders S. basale Single layer columnar cells + central nucleus Cells of epidermis : 1. Keratinocytes : Hallmark - Keratin intermediate filaments. 2. Non keratinocytes : 3 main cells : Characterstic Langerhan cells Melanocytes Merkel Cells Location S. spinosum S. basale S. basale Embryology Derived from Bone marrow Neural crest Ectoderm Content Birbeck granules. (Tennis Melanosomes Neurosecretory racquet app. on EM). granules Function Antigen presenting Cell Synthesis of Slow adapting, low (APC). Melanin (from threshold Mechano Tyrosine) receptors Markers S100, CD1a, CD207 S-100, HMB Cytokeratin 20 (Langerin : Most specific) 45, Melan-A Basement membrane zones : Hemidesmosome- Keratin Intermediate Filaments Lamina lucida Lamina densa Sublamina densa Dermato-Pathological terminologies : 00:09:37 Panniculitis : Inflammation of subcutaneous fat. Hyperkeratosis : Thickened stratum corneum. Dermatology Revision v1.0 Marrow 6.5 2023  2 01 Dermatology ----- Active space ----- Parakeratosis : Nucleated stratum corneum. Acanthosis : Thickened stratum spinosum. Spongiosis : Intraepidermal intercellular edema. eg, acute eczema. Acantholysis : Lysis of Desmosomes → Keratocytes lose attachment & become circular with a prominent nucleus (k/a Tzank/Acantholytic cells). Causes : Autoimmune : Pemphigus group. Infection : Bullous impetigo ,SSSs, HSV infection. Genetic : Hailey-hailey disease, Darrier disease. Scales in Dermatology : Branny/furfuraceous Pityriasis Versicolor Micaceous Pityriasis Lichenoides chronica Silvery white Psoriasis Collarete Pityriasis rosea Fish like Ichthyosis vulgaris Annular V/s Discoid lesions : Annular Discoid/Nummular Ring shaped lesion Coin shaped lesion Active periphery Centre & periphery active Tinea corporis, Pityriasis rosea (herald patch), BB leprosy Discoid eczema, DLE Lines in Dermatology : Langer's lines : Blaschko lines : Lines of normal skin development. Conditions distributed along these include skin tension lines. incontinentia pigmenti Incisions along (X-linked dominant). these create a cosmetically better scar. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 1 01 3 Uses of Diascopy : ----- Active space ----- 1. On diascopy Erythema produces a blanching while Purpura produces a non-blanching response d/t extavasation of RBCs. 2. Apple jelly nodules in granulomatous diseases like Lupus vulgaris (cutaneous TB), Sarcoidosis & Cutaneous Leishmaniasis. Dermatological Investigations & Therapy : Wood’s lamp : Disease Color on Wood's lamp Erythrasma Coral red Pityriasis Versicolor Yellow fluorescence Microsporum Species Blue green Trichophyton schoenleinii Dull blue Vitiligo Milky white colour Cryotherapy : Liquid nitrogen at -196°C is used for warts & Keloid. Phototherapy : Used UV radiation. It has the following types : NB-UVB : Uses 311 ± 2nm wavelength. PUVA : Uses Psoralen (photo sensitiser) + UVA. Indications : Psoriasis, Vitiligo, Atopic dermatitis. Appendages & disorders 00:20:07 Alopecia : Loss of hair. a. Non-cicatricial alopecia (Non scarring) : 1. Patchy : Alopecia areata, Trichotillomania, 2° syphillis, Non inflammatory type of Tinea capitis (Black dot & Grey patch) 2. Diffuse : Secondary to stressor events. Anagen effluvium (2°to chemo/radiotherapy; occurs after 3-4 weeks) Telogen effluvium (2° to systemic stress- COVID 19, pregnancy; 3-4 months) 3. Patterned : Androgenetic alopecia. 4. Systemic : SLE, Thyroid dysfunction. Alopecia areata : Autoimmune disorder that targets the anagen hair bulb. Circular patch Circular patch of complete hair loss. Exclamation mark hair with broad distal & tapering proximal end. Nail findings : Fine, regular superficial pits. Rx : For localised : Intralesional steroids like Triamcinolone. For extensive disease : Systemic steroids. Exclamation mark hair Dermatology Revision v1.0 Marrow 6.5 2023  4 01 Dermatology ----- Active space ----- Trichotillomania : Incomplete loss of hair within patch. Perifollicular hemorrhages. Androgenetic Alopecia : Male androgenetic alopecia Female androgenetic alopecia (Hamilton classification) (Ludwig classification) Fronto temporal recession Frontal hairline maintained. Balding of vertex. Diffuse thinning along central scalp Rx : Minoxidil : 2% for women; 5% for men. Finasteride : 5a reductase inhibitor ( se levels of Dihydrotestosterone). b. Cicatricial alopecia (scarring) : 1. Papulosquamous : Lichen planus. 2. Granulomatous : Sarcoidosis. 3. Connective tissue disease : DLE, Discoid lesions of SLE. 4. Infections : Tinea capitis (inflammatory : Favus & Kerion). Frontal fibrosing alopecia : Fronto temporal area scarring a/w Madarosis. Disorders of Sweat Glands Eccrine & Apocrine glands : Eccrine glands Apocrine glands Function : Produce sweat Produce body odour Merocrine secretion (intact cell border) Apocrine secretion (cell apex pinched off) Blockage causes Miliaria Blockage causes Apocrine miliaria Fox fordyce disease/Apocrine miliaria : Lesions : Pruritic, skin coloured papules over axilla or areola of nipple. Rx : Topical steroids/retinoids. Fordyce spots : Yellow micro papules usually over upper lip. Are ectopic sebaceous glands (no association to hair follicles). Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 1 01 5 Acne Vulgaris : 00:28:13 ----- Active space ----- Pathogen : Propionibacterium/cutibacterium acnes. Comedonal acne Rx : Topical retinoids : Tretinoin, Adapelene. Stage 1 Open - black Closed- white Predominantly Topical retinoids + topical antibiotics (Abs) Stage 2 papules (Clindamycin, Nadifloxacin). Predominantly Topical retinoids + oral Abs (Azithromycin, Doxycycline, Stage 3 pustules. Minocycline) ± Benzoyl peroxide. Nodulocystic acne Oral retinoids : Isotretinoin (13 cis retinoic acid). M/c side Stage 4 (Most severe). effect : Cheilitis. It is a category X (teratogenic) drug White comedome Papules Pustules Nodulocystic Black comedome Topical steroids should never be used in Mx of acne. Acne not responsive to antibiotics, Oral Retinoids → Suspect Hormonal acne. Cutaneous changes of Hyperandrogenism : SAHA Syndrome. Seborrhoea. Hirsutism. Acne. AGA (early onset). Rosacea : Chronic inflammatory facial dermatoses commonly triggered by vasodilators such as sunlight, spicy food, alcohol, hot beverages. Lesions : Papules & pustules on a erythematic & telengiectatic background. Comedones absent. Distribution : Along convexities of face (cheek, nose & forehead). Rx : Antimicrobials : Topical metronidazoles or oral doxycycline. Types : a. Erythemato-telengiectatic type. b. Papulopustular. c. Phymatous type / Rhinophyma (Potato nose) : Thick skin over the nose with irregular surface nodularities. Pathology : Hypertrophy & fibrosis of Sebaceous gland. Rhinophyma Dermatology Revision v1.0 Marrow 6.5 2023  6 01 Dermatology ----- Active space ----- Nail disorders : 1. Leukonychia : White nails. 2. Mees lines : Transverse white bands a/w Chronic arsenic poisoning. 3. Muehrcke’s Bands : Transverse paired white bands in Hypoalbuminemia. 4. Lindsay’s nails : Proximal half white, distal half brown ; in chronic renal failure. 5. Terry’s nails : Proximal 90% white, distal brown band ; in chronic liver failure. Bullous diseases 00:34:15 Bulla : Clear fluid filled lesion measuring > 1 cm (Vescicles measure < 1 cm) Bullous diseases Immuno-bullous Mechano Bullous aka Level of split Epidermolysis bullosa (EB) : Intraepidermal Subepidermal Blisters on areas of friction in a child/baby Pemphigus EB Simplex - K5/14 Junction EB - Laminin Pemphigoid Dermatitis Linear Dystrophic EB - Collagen 7 herpetiformis IgA dermatosis. /Anchoring fibril. Flaccid blisters & erosions Suprabasal split Row of tombstone app in Pemphigus vulgaris Immunobullous Disorders Pemphigus Pemphigus vulgaris Bullous pemphigoid Dermatitis herpetiformis foliaceus Clinical Crusts & Flaccid blisters Large tense, Intensely pruritic papulo features shallow which easily itchy bullae on vesicles; on scratching erosions on erode (tend to erythematous skin form grouped seborrheic extend with no over flexor surfaces. excoriations on extensor areas. No tendency to heal), 10-30% have oral surfaces. oral lesions oromucosal lesions lesions. common. On Blisters in Acantholytic Subepidermal blister Subepidermal blister Tzank superficial blisters formed in with eosinophil rich with neutrophils in smear & layer of suprabasal layer infiltrate. dermal papillae : Histology epidermis of epidermis Papillary tip micro abscess. Immuno IgG Intraepidermal IgG + C3 deposits IgA deposits over BMZ patho- deposits intercellular over BMZ in linear + dermal papillae in logy deposits of IgG + pattern. granular pattern. C3 : Fish net app. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 1 01 7 Target Dsg 1 Dsg 3, Dsg 1 BPAG 2 (BPAg Epidermal trans ----- Active space ----- antigen 180kDa)/ BPAG glutaminase 3 1(BPAg 230kDa) +ve Nikolsky sign -ve Nikolsky sign HLA DQ2, DQ8. Bulla spread Bulla spread sign Common a/w gluten sign : Irregular : Regular round sensitive enteropathy. angulated margins. margins. Rx High dose Low dose systemic Gluten (Barley Rye systemic steroids. steroids Oats Wheat) free diet. Cyclophosphamide Dapsone (inhibits (s/e: hemorrhagic neutrophil chemotaxis) cystitis). Rituximab : Anti CD20. Tense blisters on flexor surface Subepidermal Bulla in Bullous pemphigoid Dermatitis herpetiformis Pemphigus vulgaris Dermatitis herpetiformis Bullous pemphigoid Chronic bullous disease of childhood/linear IgA dermatosis : Immuno bullous disorder mediated by IgA. Subepidermal split. Annular arrangement of vesicles give a cluster of jewels/string of pearls app. Rx : Dapsone. Dermatology Revision v1.0 Marrow 6.5 2023  8 02 Dermatology ----- Active space ----- DERMATOLOGY REVISION 2 Pigmentary disorders 00:00:15 Disorders of Hyperpigmentation : a. Melasma : Lesion : Symmetrical Hyperpigmented macules. Site : Malar, Nose, Mandibular area In Pregnancy : Chloasma In Chikungunya : Chick sign (On nose) Melasma Chick sign b. Freckles and c. Lentigenes : Freckles Lentigene Melanocyte number Normal Melanocyte activity Normal Xeroderma Peutz jegher syndrome (AD + Mucosal lentigenes + Associated with Pigmentosa Hamartomatous GI polyps) Image d. Congenital Melanocytic Nevus (CMN) : Genetics : Congenital Surface : Hypertrichosis with Well demarcated borders Giant CMN : Size > 20 cm → 2.5% risk of melanoma. e. Becker’s nevus : Genetics : Acquired Surface : Unilateral Hypertrichosis Site : Chest & Upper shoulder. f. Dermal Melanocytosis : (Aka Ceruloderma) Blue slate grey coloured lesions. i. Mongolian spot : Age : Infants. Site : Lower back Fate : Spontaneous resolution Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 2 02 9 ii. Nevus of ota & iii. Nevus of ito ----- Active space ----- Nevus of ota Nevus of ito Symmetry Unilateral Unilateral Nerve V1, V2 of trigeminal N Post. Supra clavicular N, Lat. Brachial cutaneous N Site Face & (sclera in 2/3rds) Shoulder, Scapular region Image Disorders of Hypo/Depigmentation : 00:06:00 a. Albinism : Defect in : Tyrosinase. Types : Occular → Only eyes Occulo-cutaneous → Eyes, skin & hair. Applied aspect : Albinism Oculocutaneous Albinism + Recurrent Infections + Giant granules with neutrophils (On PS) → Chediak hegashi syndrome (AR). b. Piebaldism : Inheritance : AD Defect : Neural crest Lesion : White Forelock Piebaldism c. Nevus Depigmentosus : Defective transfer of melanosomes to Keratinocytes. d. Nevus Anemicus : Congenital white patch d/t vasoconstriction. e. Vitiligo : Acquired autoimmune destruction of melanocytes. Vitiligo Segmental Non segmental Unclassified/ Onset : childhood Types Undeterminded Symmetry : Unilateral Acrofacial : Face, head and Focal : Feature : Doesn't cross distal extremities Small isolated midline, ± Leukotrichia Mucosal : > 1 mucosal site depigmented lesions Vulgaris : M/c Universal : > 80-90% body involved. Dermatology Revision v1.0 Marrow 6.5 2023  10 02 Dermatology ----- Active space ----- Focal Segmental Acrofacial Vitiligo Universal vitiligo vitiligo vitiligo vulgaris vitiligo Clinical features of vitiligo : Vitiligo Treatment : 1. Topical : Corticosteroids Tacrolimus (calcineurin inhibitor). 2. Systemic : Steroids, Azathioprine. Depigmented True Leukotrichia macule Koebner + 3. Phototherapy : Narrow band UVB (311 ± 2nm). f. Chemical Leukoderma : Chemical induced melanocyte destruction Rubber footwear : Monobenzyl ether of hydroquinone (MBEH). Bindi Dermatitis : Para tertiary butyl phenol (PTBP). Papulosquamous disorders 00:12:07 Chronic plaque psoriasis Psoriasis Pustular psoriasis Erythrodermic psoriasis Psoriatic arthritis Papulosquamous disorders Lichen Planus Acute, Self limiting M/c trigger HHV-7. Pitryasis Herald patch (1st lesion). Rosea Collarette scales. Christmas Tree Pattern (Along langer lines). Pityriasis Follicular papules Erythroderma with rubra pilaris islands of sparing Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 2 02 11 Psoriasis : ----- Active space ----- Chronic inflammatory T celldis involving skin & ± multiple systems. Pathogenesis : Epidermis : Hyperproliferation + Epidermal transit time. Psoriasis Vulgaris Dermis : Inflammation. 1. Chronic plaque psoriasis/ psoriasis vulgaris : Lesions : red scaly papules & plaques. Pinpoint bleeding Scales : Silvery white over extensor surface. If flexor surfaces → Inverse psoriasis. Auspitz sign : On scrapping psoriatic lesions with a glass slide, Silvery white scales Bulkeley membrane Grattage Test Pinpoint bleeding spots Kobner’s phenomenon/ Isomorphic response : New lesions develop along the line of trauma. Indicates active disease. kobner’s Phenomenon True KP Pseudo KP Rare causes Psoriasis & Vitiligo Viral warts. Darier disease. Lichen planus. Molluscum contagiosum. Lichen nitidus. Nail changes : Multiple Coarse irregular Subungal Distal Oil drop sign/ Salmon patch deep pits. (M/c) Hyperkeratosis Onycholysis (Pathognomic) 2. Pustular psoriasis : Cause : Abrupt stoppage of systemic steroids Lesions : Multiple pustules like Lakes/sheets of pus. Types : Von Zumbusch : Acute generalised form. Impetigo herpetiformis : Pustular psoriasis of Pregnancy. 3. Erythrodermic psoriasis/ Exfoliative dermatitis : Erythema ± scaling involving >90% BSA. Exfoliative Psoriatic 4. Psoriatic arthritis : dermatitis arthritis Seronegative arthritis classically involving DIP joints. Dermatology Revision v1.0 Marrow 6.5 2023  12 02 Dermatology ----- Active space ----- Histopathology of all psoriasis : Thinning of SG MM abscess : Collection of neutrophils Rx of all Psoriasis (except pustular) Rx of Pustular psoriasis : If < 10% BSA involved : For non-pregnant patients : Topical steroids/Emolients. Acitretin (Oral retinoid). If > 10% BSA involved : For Pregnant patients : Phototherapy/Systemic drugs. 1st DOC : Systemic steroids. 2nd DOC : Cyclosporine. Other Rx modalities : Targetted therapy (Biologics) Small molecules IL 12/23 Ustekinumab PDE-4 inhibitor : Apremilast. IL 23 Guselkumab/ Rizankizumab JAK inhibitors : Tofacitinib Anti TNF α Infliximab, Etanercept, adalimumab (JAK1/3 -) IL 17 A Ixekizumab, Secukinumab Lichen planus : 00:22:00 Chronic immune mediated skin disease, M/c triggered by dental amalgam. 6P’s : Purple Pruritic Polygonal Papules Plaques Plain topped. Magnifying lens LP lesions Wickham's striae (reticular pattern) Distribution : flexor surfaces. Phenomenon : True kobener’s. Oral lesions in Oral lesions : lacy white reticular pattern (40-60% patients). Lichen planus Nail changes : M/c → Thinning of nail plate (Characteristic : Pterygium of nail) Hair changes : Scarring Alopecia. Wickham's striae Flexor aspect Oral lesions Thinning nail plate Pterygium Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 2 02 13 Histopathology : ----- Active space ----- Rx : Topical steroids. Hitamine related disorders 00:26:34 1. Urticaria : (Dermal edema) Lesion : Wheal → Itchy transient plaque with central pallor & peripheral erythema. Dermographism : Stroking the skin with a blunt object → exaggerated wheal flare. Dermographism Wheal 2. Cutaneous Mastocytosis (AKA Urticaria pigmentosa) Mast cell proliferation → hyperpigmentation Mast cell stain : Toluidene blue. Darier sign : Erythema + urticarial halo. 3. Hereditary angioedema Autosomal Dominant inheritance, C1 esterase inhibitor. Recurring episodes of non pitting edema & no wheals. Eczema 00:28:50 Classification based on etiology Classification based on onset Eczema Erythema, Edema, Acute Vesicles, oozing, Exogenous Endogenous crusting. Contact dermatitis Seborrheic Stasis Eczema Irritant Allergic Pytriasis alba Lichenification : Nummular Hyperpigmentation Chronic + thick skin + Pompholyx exaggerated skin markings. Dermatology Revision v1.0 Marrow 6.5 2023  14 02 Dermatology ----- Active space ----- Exogenous eczema : Contact Dermatitis Irritant Allergic Predisposition On exposure Genetic Reaction Direct tissue damage Type 4 HS (Immune mediated) Boundary Restricted to site of Tends to disseminate beyond contact Metal : nickel Cement : Potassium dichromate Examples Detergent, Diaper Bindi : PTBP dermatitis Hair dye : Para phenylene diamine Partheneium : Sesquiterpene Lactone (M/c in plants) Identified by white Image flower buds Additional points on Allergic dermatitis : Dx by : Patch test. Type 4 HS reaction. Read at : 2 days or 48 hours. Best read at : 4 days or 96 hours. Allergens applied on back Endogenous eczema : Seborrhoeic dermatitis/Dandruff Etiology : Malassezia Lesion : Greasy yellow scales visible on scalp & face (nasolabial folds). Subtype : Infantile Seborrhoeic/Cradle cap dermatitis. Stasis/ gravitational eczema Endogenous Eczema A/s with chronic venous insufficiency. C4a : Pigmentation + eczema (CEAP classification). Pityriasis alba Seen in Children with H/o atopy. Hypopigmented white scaly macules on face. D/d : Indeterminate hansen's (scales -ve here). Nummular/ Discoid eczema Disc shaped lesion. Centre + periphery is active. Pompholyx/ Dishydrotic eczema Deep seated vesicles on palms & soles. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 2 02 15 Atopic Dermatitis 00:34:47 ----- Active space ----- Chronic relapsing inflammatory skin disease. Type 1 HS reaction. Atopic triad : Allergic Rhinitis + Atopic (Dermatitis + Asthma). Clincial phases Infantile Childhood Adult Timeline Upto 2 yrs 2 yrs - puberty > puberty Distribution Face, scalp, extensors Flexures (Cubital, popliteal fossa) Lichenification flexures Image Skin changes : White dermographism : White line on stroking the skin. Headlight sign : Eczema of malar area sparing perinasal, perioral areas. Headlight sign Eye changes : Keratoconus : Conical cornea. Shield cataract : Anterior subcapsular. Dennis morgans fold : Infraorbital fold. Dennie Morgans Hertoghe’s sign : Lateral madarosis d/t continous. Fold Diagnostic criteria → Hanifin + Rajka criteria. 1. Hallmark feature : Intermittent & intense Pruritis 2. Typical morphology and distribution. 3. Chronic/ chronically relapsing dermatitis. 4. Personal/ family history of Atopy. IOC : Clinical examination. Rx : Topical : Steroids. Systemic : Steroids/ cyclosporine. Applied aspect : Male child presenting with recurrent infections + Atopic eczema + Thrombocytopenia → Wiskott Aldrich Syndrome (X-Linked Recessive). Dermatology Revision v1.0 Marrow 6.5 2023  16 03 Dermatology ----- Active space ----- DERMATOLOGY REVISION 3 Bacterial Skin Infections 00:00:23 Pyoderma Follicular Non Follicular Etiology : S. aureus Folliculitis Furuncle/Boil Carbuncle Follicle oriented Follicle + Perifollicular Multiple follicles + Contiguous area pustule area M/c site : Nape of neck a/w DM Localised Spreading Deep Superficial Ecthyma Impetigo Superficial Deep Bullous Non-Bullous/ (S. aureus) Impetigo contagiosa Erysipelas Cellulitis Varnish crust Erysipelas Cellulitis Upper 1/2 dermis + lymphatics Lower 1/2 dermis + Subcutaneous tissue Well demarcated & rasied Ill demarcated & diffuse Topical Antibacterials used in pyoderma : Fusidic Acid Mupirocin Inhibit Ozenoxacin MRSA Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 3 03 17 Staphylococcal scalded skin ----- Active space ----- Syndrome : S. areus Toxin mediated Sheet like peeling of epidermis True Nikolsky sign. Acute Paronychia d/t Meningococcaemia Staphylococcal scalded Targer Ag : Dsg 1. S. areus infection Petichael rashes + skin syndrome Subcorneal split & No Signs of meningitis mucosal involvement. Corynebacterium skin infections Erythrasma : C. minutissimum. Reddish-brown hyperpigmentation (axilla and groin). Wood’s lamp : Coral Red fluorescence Pitted Keratolysis : Micrococcus/Kytococcus sedantarius. Trichomycosis Axillaris : C. Tenuis. Pseudomonas skin infections Ecthyma Gangrenosum. Hot tub folliculitis Green nail syndrome Cutaneous Tuberculosis Tuberculosis Verrucosa Cutis/ Anatomist’s wart. Lupus Vulgaris (M/c in adults). Lesion : Annular infiltrated plaques with peripheral extension. M/c sites : Face, buttocks & Extremities Diascopy : Apple jelly nodules. Scrofuloderma (M/c in child). Lupus Vulgaris M/c site : Cervical LN. Cutaneous anthrax : Etiology : Bacillus anthracis Lesion : Malignant pustule/eschar + Rim of vesicles Scrub Typhus : Cause : Orientia tstsugamushi Vector : Trombiculid mite Skin lesion : Eschar + erythema Rx : Doxycycline (DOC) Pregnancy : Azithromycin Note : Central scarring → Lupus Vulgaris Central clearing → Tinea Central crusting → Leishmaniasis Dermatology Revision v1.0 Marrow 6.5 2023  18 03 Dermatology ----- Active space ----- Fungal Skin Infections 00:12:48 Superficial mycosis : 1. Pityriasis Versicolor : (Scaling colours) Etiology : Malassezia globosa > M. furfur Scales : Fine branny scales. Lesions : Hypo + Hyper pigmented macules. M/c site : Trunk. Fine branny Ix : 10% KOH mount : Short hyphae + Round spores. furfuraceous Spaghetti meat ball appearance. scales Wood’s lamp : Yellow fluorescence. Rx : Topical (1st line) : Azoles + Selenium sulphide. Systemic : Fluconazole. 2. Candidiasis : Candidial skin infections Oral thrush Intertrigo Balanoposthitis Can be macerated Radial fissuring rubbed off plaques + around prepuce. Satellite A/s with DM. Candida Intertrigo pustules Rx : Fluconazole/Clotrimazole. 3. Dermatophytosis : Types of Taenia T. pedis T. cruris T. capitis T. corporis Onychomycoses Athlete's Foot Groin Scalp Trunk Nail plate 4th toe webspace (M/c) Tinea corporis & cruris lesion Onychomycosis : Subungal hyperkeratosis Subungal Yellowish discolouration of nail plate, No pitting Hyperkeratosis Note : Psoriasis shows Subungal hyperkeratosis with Pitting +. Subtype : Distal Lateral subungal onycho-mycosis (DLSO) (m/c type). Rx of Onychomycosis : Nail lacquer Yellow nail plate 1) Amorolfine 5%. 2) Ciclopiroxolamine 8%. 3).Terbinafine. discoloration Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 3 03 19 ----- Active space ----- T. capitis (Scalp) Inflammatory Non-Inflammatory Favus Kerion Black dot Grey patch Disease Etiology Clinical features T. tonsurans Black dot Endothrix involvement T. violaceum Grey Microsporum canis Ectothrix involvement Favus patch Favus T. schoenleinii Scutula H/o contact with a pet. Kerion Zoophilic fungi : Boggy swelling with easily pluackable hair. (Seen in T. mentagrophytes Regional LN enlarged. children) T.verrucosum Kerion Ix : KOH mount Rx : 1. Azoles : a. Imidazoles : Ketoconazole, Luliconazole, Clotrimazole. b. Triazoles : Flucanazole, Itraconazole. 2. Allylamines - Terbinafine. Note : Enzyme involved in terbinafine resistance in dermatophytosis : Squalene epoxidase. Subcutaneous mycoses : (implantation mycoses) 00:21:36 Sporotrichosis Chromoblastomycosis Mycetoma 1. Sporotrichosis/ Rose Gardener’s disease Etiology : Sporothrix schenckii Lesions : Nodulo-ulcerative (Along lymphatics of extremities). HPE : Asteroid body. Rx : Itraconazole. D/d of sporotrichoid lesions : Nocardiosis, Cutaneous Leishmaniasis, Tularemia, Atypical Mycobacterium (M. marinum). 2. Chromoblastomycosis/ Verrucous dermatitis Etiology : Dermataceous fungi in Vegetative trauma like Fonsecaea pedrosoi, Phialophora verrucosum. Lesions : Verrucous plaques + Black dots on surface. Ix : KOH mount → Medlar/Sclerotic, Copper penny bodies Rx : Itraconazole. Cauliflower lesions Dermatology Revision v1.0 Marrow 6.5 2023  20 03 Dermatology ----- Active space ----- 3. Mycetoma : Mycetoma Eumycetoma Actinomycetoma Fungi : Bacterias : Actinomadura madurae Madurella Nocardia sp. species Streptomyces sp. Tumefaction Triad Discharging sinuses Granules (Colonies of microbes) Black/ Dark Pale cream Rx Antifungals Welsh regimen : Amikacin + Cotrimoxazole Mycetoma Viral Skin Infections 00:27:16 Orolabial herpes : (AKA Fever blister/ Cold sore) Etiology : HSV-1 Lesions : Grouped vesicles. Site : Lip Margin. Rx : Acyclovir 400mg 1-1-1 x 5 days. Varicella : Etiology : Varicella zoster. Period of infectivity : Until all lesions crust. Lesion : Dew drop on rose petal appearance. Pleomorphic rash. Site : Trunk (Centripetal distribution). Vesicle on red base Herpes : (Shingles) Reactivation of varicella. Eruptive phase lesions : Unilateral, Dermatomal, Painful grouped vesicles over red base. Complication : Post herpetic neuralgia (allodynia is seen). Shingles Rx of Varicella & Herpes : Acyclovir : 800mg 1-1-1-1-1 x 7 days OR Valacyclovir : 1g 1-1-1 X 7 days. Oral hairy leukoplakia : Etiology : EBV. Features : HIV infected patient. White corrugated plaque on lateral border of tongue Can’t be rubbed off. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 3 03 21 Kaposi Sarcoma : ----- Active space ----- Etiology : HHV-8. Lesions : Purplish plaques/nodules. Features : Low grade tumor. Aids defining illness. Kaposi sarcoma Molluscum contagiosum : Family : Pox virus (Adult : MCV-1, Child : MCV-2). Lesions : Pearly white, dome shaped, umbilicated papules. Site : Children → Over face. Adults → Anogenital region Named phenomenon : Pseudo Kobners (also in viral warts). Rx : Self limiting. Physical method : Curettage Molluscum contagiosum Topicals : Imiquimod-TLR7A Agonist (also in anogenital warts). Cup shaped invagination Molluscum contagiosum like lesions in HIV of epidermis into dermis Only skin Disseminated Molluscum Skin + Lung Disseminated Histoplasma Henderson Patterson bodies : Eosinophilic & Skin + CNS/ Disseminated Intracytoplasmic Meningitis Cryptococcus Other Viral Infections : Verruca vulgaris/ 5th disease : Hand Foot Mouth disease : Common warts Parvo virus B19 Etiology : Coxsackie A16, Enterovirus 71. Etiology : HPV 2, 4, 27 Face : Slapped cheek appearance. Vesicular lesions on palms & soles, Trunk : Reticulate rash. buttocks & oral cavity. Parasitic Skin Infections 00:36:04 Ectoparasitic infections 1. Scabies : Etiology : Sarcoptes scabiei var hominis/ Itch mite. Lesions : Exocoriations and burrow at level of stratum corneum (by female parasite). Burrows Dermatology Revision v1.0 Marrow 6.5 2023  22 03 Dermatology ----- Active space ----- Note : Burrow is not seen in case of animal scabies. Distribution : Circle of Hebra (Face spared in adults d/t sebum activity). Rx : Permethrin 5%, Ivermectin 200 g. Special forms of scabies : Infantile scabies : Face involved, Vesicles on Palms & soles. Norwegian scabies/ Crusted scabies : Most severe and contagious form. Seen in Immunosuppressed people. Rx : Add Salicylic acid to the Rx. 2. Pediculosis : P. capitis (Head louse) P. corporis (Body/ clothing louse)/Vagabonds disease) : Site : present in seams of clothing. Lesions : Morbus errorum. Pthriasis pubis (Pubic louse) : Pruritis, Blue macule on lower abdomen. Migratory infective skin lesions : 1. Cutaneous Larva Migrans : Etiology : A. brasiliensis, A. caninum. Lesion : Migratory, serpiginous tract. Rx : Albendazole/ Ivermectin. 2. Leishmaniasis : Leishmaniasis Cutaneous/ Delhi boil Post kala-Azar Dermal (PKDL) Post Kala-Azar Dermal Hailing from Bihar with prolonged fever. Trunk : Hypopigmented macules. Face : Infiltrated Papulonodular lesions. Central crusting On Geimsa stain : LD bodies (amastigote form). Volcano ulcer. Rx : Miltefosin. Note : DOC in Kala Azar PKDL Lepromatous leprosy Liposomal Nerve Involvement ---- +++ Amphotericin B. Split skin smear ---- AFB ++ Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 4 04 23 DERMATOLOGY REVISION 4 ----- Active space ----- Hansens disease 00:00:06 Chronic, inflammatory granulomatous disease. TT LL Organism : AFB Few Numerous Mycobacterium leprae CMI Good Poor M. lepramatosis Skin lesions 1-3 Multiple Ridley Jopling classification (Based on CMI) : Nerve 1 Multiple TT, BT, BB, BL, LL. involvement Types of leprosy Features Tuberculoid (TT) : 1-3 skin lesions. Annular plaque with central clearing & well-defined margin. A/w : Granuloma, anesthesia, alopecia, anhydrosis. Side profile : Saucer right way up appearance. Borderline tuberculoid (BT) : 3-10 lesions. Well/ not so well-defined margins. Satellite lesions present. Mid-borderline (BB) : AKA Dimorphous leprosy. 10-30 lesions. (Polymorphic). Geographic map like appearance. Inner punched out margin (swiss cheese appearance). Sloping outer margin (inverted saucer appearance). Borderline lepromatous (BL) : Skin lesions & Nerve thickening almost symmetrical. Inverted saucer appearance. Lepromatous (LL) : Systemic disease. Symmetrical. Early features : Epistaxis, pedal edema. Late features : Leonine facies, glove & stocking neuropathy. Indeterminate Hansens : H/o : Child from endemic areas (Bihar, UP, TN). Hypopigmented macules over the face. No scaling/ itching. Neuritic Hansens : Skin : Normal; Nerves : Invoved. Nerve Bx → Radial cutaneous nerve or Sural nerve. Clinical Features & Management of Hansen’s disease : 00:06:13 Deformities : Madarosis. Trophic ulcer. Saddle nose. Claw hand Foot drop (ulnar nerve) (common peroneal nerve). Saddle nose Madarosis Dermatology Revision v1.0 Marrow 6.5 2023  24 04 Dermatology ----- Active space ----- Cranial nerves : 7th CN (lagophthalmus) > 5th CN involvement ( corneal sensation). Cardinal features : 1 of 3 should be +ve for diagnosis. 1. Skin : Hypopigmented lesion + Definitive loss of sensation. 2. Nerve : Enlarged peripheral nerves + (sensory/motor deficit). 3. Slit skin smear : +ve for acid fast bacilli. HPE of lepromatous leprosy : Thickening of greater auricular N. Grenz zone (subepidermal free zone) Lepra cells/Virchow’s cells (Foamy marophages + AFB) Note: Stain for M. leprae : Fite Faraco stain. Management (in adults) : Paucibacillary Multibacillary Skin lesions 1-5 ≥6 Nerves No nerves/ 1 nerve > 1 nerve SSS for AFB -ve +ve Duration of Rx 6 months 12 months No. of drugs 3 3 Treatment Rifampicin (D1 : 600 mg/month), Dapsone (D1-D28 : 100 mg/day) Clofazamine (D1 : 300 mg/month; D2-D28 : 50 mg/day) NLEP : 3 drugs for PB & MB (same as WHO). Chemoprophylaxis (for contact ≥2 yrs) : Single dose Rifampicin (except in TB, leprosy pts). Contact → With a new case for prolonged duration (20 hrs/wk for 3 months in last 1 yr). Immune mediated/ episodes of acute inflammation. Lepra reaction 00:15:30 Type 1 Type 2 (Erythema nodosum leprosum) Lucio phenomenon Type 4 HS reaction Type 3 HS reaction Seen in lucio leprosy Existing lesion : Red & tender New, red, tender nodules Nerves +++ Fever ++ ; Seen in BL, LL Management : Continue MDT ; DOC : Systemic steroids. Note : Thalidomide (given in Type 2 Lepra reaction) is avoided in pregnancy (Teratogen) Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 4 04 25 Sexually transmitted diseases 00:18:34 ----- Active space ----- Anogenital warts/condyloma acuminata Etiology : C/F : Asymptomatic pink HPE : Koilocytes pointed papules & plaques. seen. (Squamous HPV 6, 11 (low risk) : 90% Cauliflower-like lesions. epithelial cell, HPV 16, 18 (high risk) : 10% hyperchromatic Rx : Podophyllin, Imiquimod (TLR-7 agonist). nucleus, Pregnancy : Cryotherapy : -196˚C (TOC), perinuclear halo) Tri Chloro Acetic acid 70-80% Note : Cauliflower like lesion on genitals : Anogenital warts.. Cauliflower like lesion on foot : Chromoblastomycosis. Urethritis : Gonococcal urethritis Non-gonococcal urethritis Neisseria gonorrhoeae Chlamydia trachomatis D-K (M/c), Ureaplasma urealyticum, Mycoplasma genitalium, Trichomonas vaginalis Profuse purulent discharge Scanty mucoid discharge Gram negative intracellular Numerous PMNs. diplococci (GNICDC) Absence of GNICDC. Inj. Ceftriaxone 500mg IM + Doxy 100 mg BD Azithromycin 1g stat (or) x one week (If Chlamydia is not excluded) Doxy 100 mg BD x 1 wk Vaginal discharge syndrome : Candidiasis Trichomoniasis Bacterial vaginosis Etiology : C. albicans T.vaginalis Altered Microflora : Gardnerella, Mobiluncus, Lactobacillus Vaginal discharge Greenish yellow, Homogenous, white, adherent (VD) : Curdy white frothy Special features : Multiple punctate Whiff test/ Amine test : Culture media to hemorrhages Vaginal Discharge + KOH → Fishy odour. differentiate various (strawberry Squamous epithelial cells + surface bacteria : k/a species of candida : cervix) Clue cells (>20% on wet mount for diagnosis). Chrom-agar. Pruritis ++ Dermatology Revision v1.0 Marrow 6.5 2023  26 04 Dermatology ----- Active space ----- Syphilis : 00:25:38 Etiology : Treponema pallidum. Syphilis Congenital Acquired In-utero transmission Early Late (first 2 yrs of life) (>2 yrs of life) Hutchinson's triad : Interstitial keratitis. Hutchinson's teeth. SNHL. Hutchinson's teeth (notched upper central incisors) Note : Hutchison teeth is not same Vesiculobullous lesions : as Mulberry molars (Abnormal 1st Syphilitic pemphigus lower molars with excessive cusps) Diday Kassowitz Law : Syphilis in pregnancy. Untreated Series of pregnancies Likelihood of infection in fetus syphilitic mother (subsequent pregnancies) reduces Acquired syphilis : (sexual/ blood transfusion) Primary syphilis Secondary syphilis IP : 9-90 days Hematogenous spread. C/F : Hard chancre (single, clean based, Constitutional symptoms. indurated, non-tender, not bleed on touch) Rash : Symmetric, non pruritic, polymorphic (except vesicles & bulla). Palms & soles involved. Inguinal LN : B/L, enlarged, non-tender rubbery LN. Generalised LNpathy (epitrochlear LN ++) IOC : Dark ground microscopy. IOC : VDRL/ Rapid plasma reagin test (RPR). Slender organisms Note : IOC for neurosyphilis : CSF-VDRL. (corkscrew motility). Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 4 04 27 Rx of acquired syphilis : ----- Active space ----- 1°, 2° & early latent syphilis : Late latent & 3° syphilis : Neurosyphilis : Single dose of 3 doses of I.V aqueous Inj. Benzathine Peniciliin Inj. Benzathine Peniciliin crystalline Penicillin (2.4 million units), deep IM. weekly once. 10 - 14 days. Jarisch Herxheimer Reaction : (Self resolving) Syphilis pt on Benzathine Penicillin → Lysis of T. pallidum → Release of IL-6, IL-8, TNFα → Within few hrs : fever, myalgia, hypotension, worsening of skin lesions. Other STDs : Chancroid Lymphogranuloma venerum Donovanosis/ Granuloma inguinale Etiology : Hemophilus ducreyi. Chlamydia trachomatis L1, Klebsiella granulomatis. L2, L3 IP : 8 - 80 days. C/F : Soft chancre (mutiple, C/F : Ulcer : Single painless, beefy necrotic, non-indurated, 1° stage : Single painless red, exuberrant granulation tender, bleed on touch). transient ulcer. tissue. Bleeds on touch. Inguinal LN : U/L Bubo + 2°/ inguinal stage : Inguinal LN : Normal. concommitant genital ulcer. Bubo (2/3rd U/L > 1/3rd B/L). Pseudo bubo +nt No concomitant genital ulcer. (s/c nodule on groin). Groove sign of Greenblatt may be seen. 3° stage : Genital elephantiasis. Males : Saxophone penis Females : Esthiomene Gram stain : IOC : NAAT. Crushed tissue smear Gram -ve coccobacilli (pool (Giemsa) : Pund cells with of fish/ railroad track app). intra-cellular donovan bodies (closed safety pin app.). Rx : T. Azithromycin 1g stat. Rx : Doxycycline 100mg BD x Rx : Azithromycin till the ulcer 3 weeks. heals. 1 g/wk x 3 wks (OR) 500 mg/day x 3 wks. Dermatology Revision v1.0 Marrow 6.5 2023  28 04 Dermatology ----- Active space ----- Herpes genitalis : 00:34:30 Etiology : HSV-2 (90%), HSV-1 (10%). Vesicles → Rupture → Multiple, grouped, tender ulcers (polycyclic margins). Inguinal LN : B/L enlarged, tender. Diagnosis : Tzank smear - Multinucleated giant cells (MNG). Rx : T. Acyclovir 400 mg TDS x 7 days. Vesicles Ulcer Tzanck smear (MNG) Syndromic management of STDs 00:40:24 Kit Colour Indication Drugs Target diseases 1 Grey Urethritis/ Cervicitis T. Cefixime 400 mg 1 STAT Gonococci Azithromycin 1 g single dose Chlamydia 2 Green Vaginal Discharge Tab Secnidazole 1 g BID Bact. vaginosis, Trichomoniasis T. Fluconazole 150 mg 1 dose Candidiasis 3 White GUD : Non-Herpetic Inj. Benzathine Penicillin Syphilis 2.4 MU IM Azithromycin 1 g single dose Chancroid 4 Blue GUD : Non-Herpetic Doxy 100mg BD x 15 days Syphilis (Allergic to Penicillin) Azithromycin 1 g single dose Chancroid 5 Red GUD : Herpetic Acyclovir 400mg TID x 7 days Genital herpes 6 Yellow Lower abdominal Pain T. Cefixime 400 mg 1 STAT Gonococci T. Doxy 100 mg BD x 14 days Chlamydia T. Metronidazole 400 mg Anaerobes BD x 14 days 7 Black Inguinal Bubo Azithromycin 1g single dose Chancroid Doxy 100mg BD x 3 weeks LGV Note : 1. GUD : Genital Ulcer Disease. 2. H/0 vaginal discharge & o/e cervical erosions → Grey kit. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 5 05 29 DERMATOLOGY REVISION 5 ----- Active space ----- Genodermatoses 00:00:28 Neurofibromatoses 1 (Von Reckling Hausens Disease) : Types Features Images Cutaneous neurofibromas. Skin colored papulo nodules. Onset In adolescents. Plexiform neurofibromas Congenital. Diffuse enlarging mass. “ Bag of worms” feel. Café au lait macules Number : ≥ 6. (Hyper-pigmented). Size : Pre-pubertal : > 5mm. Post-pubertal : > 15 mm. Axillary freckling Pathognomoniic of NF 1. (Crowe's sign). Lisch iris nodules. Pigmented iris hamartomas. Tuberous sclerosis complex (AD) : Ash leaf macules (Hypopigmented) : On trunk. Epilepsy “EpiLoA” Low VOGT’S Triad Adenoma Intelligence Sebaceum Adenoma sebaceum : Shagreen patch : Koenens tumor : Facial angiofibromas. Lumboscaral region. Periungual fibromas Reddish brown papules. Made of collagenoma. Dermatology Revision v1.0 Marrow 6.5 2023  30 05 Dermatology ----- Active space ----- Sturge Weber Syndrome (Encephalo-trigeminal angiomatoses) Sporadic. CNS : Epilepsy. Eye : Glaucoma. Skin : Port wine stain (Rx : pulse dye laser). Ichthyosis Fish like scales with no inflammation. Congenital icthyosis Ichthyosis Filaggrin defect. Vulgaris (AD) Fine, white scales. X Linked Steroid Sulfatase defect. Ichthyosis/ Brown- Black scales. Ichthyosis Associations : Corneal opacities & cryptorchidism. Nigra (XR). Lamellar Epidermal Transgluta-minase 1 defect. Ichthyosis Translucent, parchment like membrane (AR) (Neonate) : Collodion membrane. Dark, plate like,adherent scales with no areas of sparing. Associations : Ectropion & Eclabium. Xeroderma pigmentosum (AR) : Nucleotide excision repair (NER) defect. Photophobia. Freckles. Increased risk of skin Ca. Skin in connective tissue diseases 00:07:34 Lupus Erythematosus : 1. Acute cutaneous lupus erythematosus : Aka malar/ butterfly rash. Symptom : Photosensitivity. Spared : Nasolabial fold. Lesion : Erythema over malar area + Bridge of nose. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 5 05 31 2. Chronic cutaneous lupus erythematosus : ----- Active space ----- Discoid LE (MC). Discoid plaque lesions. Atrophy+ Scarred center with hyperpigmented periphery. Adherent scales → Scarring alopecia. Sites : Face, Scalp, Ears. Dermatomyositis : Proximal myopathy + Skin changes. Gottrons papules Heliotrope rash Mechanics hand Shawl sign Violaceous Violaceous macular Hyperkeratotic fissures Violaceous macular flat-topped erythema at at tips/sides of digits erythema at papules at periorbital region shoulder/upper MCP/IPx Joint back Scleroderma : 1. Morphea (cutaneous lesions) : Linear scarring alopecia (En coup de sabre) 2. Systemic sclerosis (skin & system) : Limited cutaneous SS Skin thickening is Diffuse cutaneous SS common to both Present distal to elbow & knee. Present distal to elbow & knee. Involves the face Involves the face CREST Syndrome : Type of limited cutaneous SS. Components : Calcinosis cutis, Raynauds phenomenon, Esophageal dysmotility, Telengiectasia, Sclerodactyly. Mask like facies. Pinched nose. Perioral furrows. microstomia. Salt & pepper pigmentation. Telengiectasia. Dermatology Revision v1.0 Marrow 6.5 2023  32 05 Dermatology ----- Active space ----- Henoch schoeinlein purpura/ Ig A Vasculitis : Small vessel vasculitis. Symmetric palpable purpura of lower extremities. Normal platelet count. Reactive Arthritis : Skin lesions : Hyperkeratotic papules + plaques (palms/ soles). Circinate balanitis. Keratoderma blenorrhagicum Skin, Systems & Malignancy 00:13:16 Erythema nodosum : Red tender nodules (anterior aspect of leg). MC cause : Idiopathic. MC infection trigger : Streptococci. Lofgren’s syndrome : Fever+ B/L Hilar LN + Arthritis + Erythema nodosum. Acanthosis nigricans : Hyperpigmented velvety plaques. Over axilla, neck folds. MC Cause : Obesity. Granuloma annulare : Annular arrangement of papules (Dorsum of hand). A/W diabetes mellitus. Necrobiotic collage destruction. Necrobiosis lipoidica diabeticorum : Waxy yellow plaque + surface telangiectasia over anterior aspect of leg. A/W diabetes mellitus. Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 5 05 33 Pretibial myxoedema/ Thyroid dermopathy : ----- Active space ----- Diffuse, non pitting edema. A/W Graves disease. Phrynoderma : Hyperkeratotic follicular papules. A/W essential fatty acid/ Vit A deficiency. Site: Elbows and Knees. Pellagra : Vit B3/Niacin deficiency. (Maize & Jowar based diet). Chronic alcoholism. Triad (3D) : Dermatitis (cassals necklace), Diarrhoea & Dementia. Xanthelasma palpebrarum : Symmetric yellow papules. A/W hyperlipidemia (in 50 %). Mycoses fungoides / Cutaneous T Cell Lymphoma (CTCL) : Non-Hodgkin’s Lymphoma (CD4 cells). Pautriers microabscess (Collection of Atypical T Cells). Sezary syndrome : Erythroderma + Leukemic variant of CTCL. Classical triad : 1. Erythroderma. 2. Generalised lymphadenopathy. 3. Circulating sezary cells (cerebriform nucleus). Basal cell carcinoma : Locally invasive (rodent ulcer). Metastases are rare. Translucent pearly nodule with surface telengiectasia Central necrosis Ulcer (rolled out edges) Dermatology Revision v1.0 Marrow 6.5 2023  34 05 Dermatology ----- Active space ----- Cutaneous drug reactions 00:20:06 Fixed drug eruption : Type VI Hypersensitivity reaction. Drugs : NSAIDs, Cotrimoxazole, Tetracyclines. Morphology : Circular dusky plaque. Recurs at the same site (FIXED). Heals with a very characteristic hyperpigmentation. Erythema multiforme : Cytotoxic dermatitis. MC Infection trigger : HSV 1 infection. Lesion : Target lesions. (Site: Palms and soles). Stevens Johnson Syndrome-Toxic Epidermal Necrolysis : Acute, life threatening, severe, muco-cutaneous. Etiology : NSAIDS, Antiepileptics, Sulfonamides, Antiretrovirals (nevirapine), Allopurinol (>90 % drug Induced). Classification : Basis : Epidermal Detachment (BSA) Types 30% TEN Flat Atypical Target Lesions Sheet like Have only 2 zones epidermal peeling. (instead of 3) Clinical Sign : Present on proximal Pseudo nikolski sign extremeties (keratinocyte necrosis) Treatment : Stop offending drug. Cyclosporine/ IV immunoglobulin Dermatology Revision v1.0 Marrow 6.5 2023  Dermatology Revision 5 05 35 Miscellaneous topics 00:24:22 ----- Active space ----- Lichen Nitidus : Chronic inflammatory disease of unknown etiology. Presents in children Asymptomatic shiny papules present kobners phenomenon present. Shiny papules on face Presents in children Histopathology : Ball : Chronic inflammation. Claw : Rete ridges. Claw clutching the ball appearance Cutis Marmorata : Physiologic response to cold. Occurs in infants Reticular marbling lesion. Site: Trunk & extremities. Reverse on warming. Trichothiodystrophy : Polarizing microscopy of the hair shows Tiger tail appearance Methylisothiazolinone (MIT) : Role : Preservative. Products : Liquid cosmetic & personal care productS Function : Inhibit bacterial growth in cosmetic products Dermatology Revision v1.0 Marrow 6.5 2023