Dermatology Quiz on Skin Lesions

Dermatology 1

• Topics covered include papulo-squamous diseases (dermatitis, eczema, drug eruptions, lichen planus, pityriasis rosea, psoriasis), desquamation (erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis), vesicular bullae (pemphigoid, pemphigus), and acneiform lesions (acne vulgaris, rosacea, folliculitis).

Instructional Objectives

• Identify and describe the etiology, epidemiology, clinical features, differential diagnosis, and management of various skin disorders.
• Accurately describe skin lesions using standard terms.

Skin Lesions: Standard Terms

• Number: single, multiple
• Pigmentation/color: white, flesh colored, pink, pearly, erythematous, tan-brown, salmon, black, purple, violaceous, and yellow.
• Shape & Arrangement: annular, round/discoid, linear, oval, iris/target, zosteriform, serpiginous, stellate, reticulate, morbilliform, polycyclic.
• Texture: consistency, mobility, temperature, tenderness, depth
• Borders/margins: well-defined, ill-defined.
• Type: primary (macule, tumor, patch, wheal, papule, vesicle, plaque, bulla, nodule, pustule, cyst, telangiectasia) and secondary (crust, fissure, scale, ulcer, lichenified, keloid, erosion, hypertrophic scar, atrophy, excoriation).
• Arrangement/location/distribution: localized, regional, generalized.
• Associated Changes: to be documented.

Skin Layers

• Epidermis
• Dermis
• Subcutaneous tissue (fat)

Epidermal Layers

• Stratum corneum
• Granular layer
• Spinous layer
• Basal layer
• Keratohyaline granules
• Desmosomes

Skin Cell Formation

• 4 steps: cell division (basal layer), cell differentiation, keratinization, desquamation.
• Keratinocytes divide in the basal layer; as they move up, they change shape and composition.
• Keratinocytes secrete keratin proteins and lipids to form a matrix protecting the skin.
• Outermost skin cells die and shed.

Dermis

• Contains hair follicles, nerve endings, sweat glands, and connective tissue.

Skin Exam

• Be thorough! Examine the patient in a gown.
• Use good lighting (consider magnification).
• Check scalp, palms, soles, and nails.
• Look for lesions that appear different from others.
• Note skin texture, turgor, and color.
• Document findings in detail/photograph and monitor for changes over time.
• Take a picture and compare to another picture in 6 months or 1 year.

Approach to Diagnosis (CLAMPS TN)

• Color
• Location/distribution (extent, pattern)
• Arrangement (grouped vs. disseminated & confluence)
• Margination (well- or ill-defined)
• Palpation (consistency, temperature, mobility, tenderness, depth)
• Shape
• Type (papule, macule, pustule)
• Number (single vs. multiple)

Types of Skin Lesions (images)

• Crust
• Cyst
• Macule
• Papule
• Pustule
• Ulcer
• Vesicle
• Wheal

Macule

• Non-palpable
• <1 cm diameter
• Varied pigmentation from surrounding skin.
• No elevation or depression.
• Patch: macule >1 cm diameter

Papule

• Palpable
• ≤1 cm diameter (isolated or grouped).
• Pustule: small, circumscribed papule containing purulent material.

Pustule

• Circumscribed superficial cavity with purulent exudate.
• Exudate: white, yellow, greenish-yellow, or hemorrhagic.

Plaque

• Plateau-like elevation.
• Ex: psoriasis, lichenification, patch-flat, or barely elevated plaque (atopic dermatitis/eczema).

Nodule

• Palpable, solid, fatty, or cystic, round or ellipsoidal.
• Larger than a papule (1-2 cm)
• Think of it as a large papule.
• Tumor: nodule >2 cm.

Wheal

• Irregularly shaped, elevated, edematous.
• Erythematous or paler than surrounding skin.
• Well-demarcated borders, but not stable.
• Disappears within 24-48 hours.
• Multiple wheals/rash = urticaria (hives, whelps)

Vesicle/Bulla

• Blister
• Vesicle <0.5 cm
• Bulla >0.5cm
• Well-defined
• Roof is thin
• Serum and blood.

Secondary Skin Lesions

• Crust-dried serum, blood, or exudate.
• Scales-flakes
• Erosion-epidermis defect (heals without scar).
• Excoriation.
• Ulcer - defect deeper into dermis (usually indented).
• Scar-fibrous tissue replacement.
• Atrophy-diminution of some or all layers of skin.

Keloid Scars

• Illustration of keloid scars

Describing Skin Lesions (format)

• Systematic approach/format (CLAMPS TN):
  • Color
  • Location/distribution (extent, pattern)
  • Arrangement (grouped vs. disseminated & confluence)
  • Margination (well- or ill-defined)
  • Palpation (consistency, temperature, mobility, tenderness, depth)
  • Shape
  • Type (e.g., papule, macule, pustule)
  • Number (single vs. multiple)

History

• Demographics (age, race, sex, occupation, hobbies, chemical/toxin exposure)
• Constitutional symptoms (acute vs. chronic)
• History of skin lesions (OLD CARTS)
  • HPI (History of Present Illness)
  • PMHx (Past Medical History)
  • FHx (Family History) – skin cancer/disorders
  • SocHx (Social History)
  • SexHx (Sexual History)

HX of Skin Lesion (OLD CARTS)

• 8 Key Questions
  • When did lesion appear (1st noticed)?
  • Where did lesion appear (site of onset)?
  • Does it come and go or is it constant?
  • Does it itch, hurt, or bleed?
  • How has it spread (pattern/evolution)?
  • How have individual lesions changed?
  • What are provocative factors?
  • What are previous treatments (topical, systemic)?

Desquamation

• Erythema multiforme
• Stevens-Johnson Syndrome (SJS)
• Toxic Epidermal Necrolysis (TEN)

Erythema Multiforme

• Presentation: 50% are <20 y/o, M=F.
• Cutaneous reaction (drugs, idiopathic), most commonly due to herpes simplex virus (HSV).
• Target lesions (mucous involvement, palms/soles, cornea, anterior uveitis), pruritis, or burning.
• Typical target-like lesions.
• Major: drug reaction, mucosa involvement (pharynx & larynx).
• Minor: lesions on extremities & face.

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)

• Acute, life-threatening mucocutaneous reactions
• Necrosis & detachment of epidermis.
• SJS <10% detachment, TEN >30% detachment (overlap 10-30%).
• 90% involvement of mucous membranes—ocular, oral, genital.
• Rarely present on palms/soles.
• Idiopathic or drug-induced (anti-seizure meds, sulfa, allopurinol, NSAIDs).
• Increased incidence in HIV & active cancer, F > M.

Nikolsky sign

• Ability to extend superficial sloughing by applying gentle lateral pressure elsewhere on skin.
• Pathognomonic for pemphigus and TEN.

Vesiculobullous Disease

• Bullous pemphigoid: autoimmune, elderly patients, large, tense bullae, often starts with urticarial eruption. Common in axillae, medial thigh, groin, flexor UE, lower LE, can be in mouth. Tx - PO, topical steroids 50-100mg QD or immunosuppressives.
• Pemphigus: chronic or acute, bullous, autoimmune, adults 40-60, predilection for scalp, face, chest, axillae, groin, umbilicus, usually starts in mouth, painful vesicles & bullae that rupture easily, flaccid, weeping, + Nikolsky sign. Tx - dermatologist, high dose steroids and immunosuppression.

Acne & Related Disorders

• Acne vulgaris
• Rosacea
• Hidradenitis suppurativa

Acne Vulgaris

• Inflammation of pilosebaceous units.
• Seen with comedones (must have), cysts, pustules, and/or nodules.
• Primarily in young people on face, trunk, upper arms, sometimes buttocks.
• Can result in pits, depressions, scars, or hyperpigmentation.
• More severe in males than females.
• Less common in Asians & African Americans.
• Cystic acne can be familial.

Acne Vulgaris (cont'd)

• Factors in pathogenesis: follicular keratinization, androgens, Propionibacterium acnes (bacteria).
• Follicular plugging (comedones) traps sebum, androgens produce more sebum, bacteria produce inflammation.
• Contributory factors: meds (lithium, isoniazid, steroids, OCPs), androgens, stress, occlusion/pressure, cosmetics, pomade, sweat.
• Worse in fall/winter, painful nodulo-cystic type.
• Comedones (open=blackheads, closed=whiteheads) for diagnosis.
• Labs-none required
• Course-often clears by early 20s, flares in winter and with menarche.

Acne Vulgaris (treatment)

• Treatment (mild): topical antibiotics (clindamycin, erythromycin) and benzoyl peroxide gels.
• Topical retinoids (gradual increase in strength from 0.01% to 0.05%, cream, gel, liquid, or ointment).
• Adapalene (now OTC), and tazarotene - do not use during pregnancy.
• Combination therapy best.

Acne Vulgaris (treatment cont'd)

• Treatment (moderate): same mild regimen plus PO antibiotics (minocycline, doxycycline) tapered to 50mg daily if improves. Spironolactone 25-50mg QD.

Acne Vulgaris (treatment cont'd)

• Treatment (severe): same regimen, plus PO isotretinoin for cystic or refractory acne.

Acne Vulgaris (isotretinoin)

• Complete remission in most cases.
• Works by inhibiting sebaceous gland function and keratinization.
• Extremely teratogenic, MUST have effective contraception and 2 negative pregnancy tests prior to use.
• Use caution, check lipids & transaminases and normalize doses.
• Can cause extremely dry skin and mucosa. and depression.

Rosacea

• Chronic inflammation of facial pilosebaceous units
• 30-50 years old, F>M
• Episodic erythema ("flushing and blushing").
• Stages I, II, and III: persistent erythema, telangiectasias, papules, tiny pustules, nodules.
• Note: no comedones.
• Triggered by hot liquids, spicy foods, alcohol/wine, aged cheese, sun, heat, stress
• Duration: days, weeks, or months

Rosacea (cont'd)

• Late stages: rhinophyma, metophyma, blepharophyma, otophyma, gnatophyma.
• Distribution: symmetric on the face; rarely on neck, chest, back, scalp.
• Recurrences are common, usually lifelong.
• Treatment:
  • Reduce alcohol and caffeine.
  • Metronidazole gel or cream, ivermectin cream
  • Topical antibiotics
  • PO antibiotics (minocycline, doxycycline, tetracycline) for papulopustular rosacea.
  • PO isotretinoin for severe disease
  • Surgery for rhinophyma, telangiectasia (lasers).

Folliculitis

• Inflammation or infection of superficial hair follicles.
• Perifollicular papules &/or pustules with surrounding erythema, hair-bearing skin, often pruritic.
• More common in males.
• Risk factors: prolonged antibiotic use, topical corticosteroids, hot tubs, (most common staph aureus, hot tubs → Pseudomonas aeruginosa).

Folliculitis (treatment)

• Treatment: benzoyl peroxide wash, topical mupirocin, clindamycin, erythromycin. If no improvement, PO Cephalexin.

Hidradenitis Suppurativa

• Chronic, suppurative.
• Apocrine gland skin (axillae, inguinocrural, anogenital, inframammary, rarely scalp.)
• F (axillae) > M (anogenital).
• FHx NC acne & HS.
• Unknown etiology.
• Risk factors: obesity, smoking, genetic predisposition to acne.

Hidradenitis Suppurativa (cont'd)

• Lesions: tender, open & double comedones; red nodules, abscesses, sinus tracts; "bridge" scars; hypertrophic & keloidal scars; contractures.
• Pathogenesis: follicle plugging, dilated follicle & apocrine duct > inflammation, bacterial growth > extension of suppuration/tissue destruction > ulceration, fibrosis, sinus tracts > scarring.

Hidradenitis Suppurativa (treatment)

• Usual spontaneous remission at >35 years.
• Treatment: intralesional steroids, I&D abscess, prednisone for severe pain & inflammation, surgery (excision, skin grafting), PO antibiotics (chronic low-grade disease), isotretinoin for early disease, adalimumab (Humira), Psychological support.