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23/02/2024 The skin is the window to underlying systemic diseases as it may give visible diagnostic clues to underlying disease: The Skin and Systemic Diseases By: Salsabiela Bani Hamad 1 2 Characteristic rashes associated with underlying systemic disease: Erythema multiforme: Herpes simplex virus,...

23/02/2024 The skin is the window to underlying systemic diseases as it may give visible diagnostic clues to underlying disease: The Skin and Systemic Diseases By: Salsabiela Bani Hamad 1 2 Characteristic rashes associated with underlying systemic disease: Erythema multiforme: Herpes simplex virus, mycoplasma, pneumonia, hepatitis B/C Pyoderma gangrenosum: Hematological malignancy, inflammatory bowel disease (IBD), rheumatoid arthritis Erythema nodosum: Streptococcal infection, TB, sarcoid, pregnancy, IBD, Behcet disease. Vasculitis: Hepatitis B/C, SLE, Leukaemia, lymphoma. Skin reactions associated with infections: Gianotti-Crosti syndrome Erythema Nodosum Erythema Annulare Centrifugum 3 Toxic Erythema Erythema Multiforme Erythema Migrans 4 1 23/02/2024 Toxic Erythema: Toxic Erythema: Widespread symmetrical reactive rash consisting of maculopapular erythema (looks ‘morbilliform’, i.e. measles-like). Starts on the trunk and then spreads to the limbs, blanching and may be mildly itchy. Etiologies: Viruses (measles, rubella, Epstein–Barr virus (glandular fever patients given amoxicillin classically develop toxic erythema) Bacterial infections such as Scarlet fever Parasitic infections (trypanosomiasis – sleeping sickness) Treatment: No treatment is required (only emollient and occasionally a mild topical steroid if symptomatic) Management of the underlying disease. 5 6 Erythema Multiforme: Erythema Multiforme: Systemic symptoms of the underlying infection usually precede the EM rash by 2–14 days. Two types: The rash is thought to result from an immunologically mediated type 4 hypersensitivity reaction. Slight male predominance. EM Minor: No mucosal involvement, no systemic sx) EM Major: Involvement of mucous membranes (oral, conjunctival, genital) accompanies the classic cutaneous EM rash(> systemic steroids Cutaneous: - Localized: topical steroids - Extensive: systemic steroids, methotrexate, hydroxycholroquine. 21 22 Addison’s disease Hyperpigmentation: Hypopigmentation: § Is an increase in circulating hormones with melanocyte-stimulating activity § Etiologies: Extensive: Hyperthyroidism, Addison’s disease, and acromegaly. Localized: Melasma/chloasma - In pregnancy or in those taking oral contraceptives A widespread partial loss of melanocyte functions. Seen in hypopituitarism and is caused by an absence of melanocyte-stimulating hormone. Melasma - At the forehead and cheeks - It may fade slowly if ultraviolet light is excluded from the affected skin using daily sunblock. 23 24 6 23/02/2024 Acanthosis nigricans: Necrobiosis lipoidica: Asymptomatic velvety dark symmetrical plaques usually affecting the posterior and lateral aspects of the neck, axillae, and arm flexures Necrobiosis indicates necrosis of the underlying connective tissue and replacement of degenerating collagen fibers with lipid material. Associated with DM (especially type 1) Usually at dark skin individual Associations: Obesity (m.c) Insulin resistance Diabetes Thyroid disease Lupus. More extensive and rapidly evolving AN, particularly involving the lips/tongue/palms may herald underlying malignancy, particularly of the gastrointestinal (GI) tract. Checking of fasting glucose is recommended. It usually occurs over the shin. Not related to DM severity Not affected by blood sugar control Treatment: intralesional steroids, surgery. Treatment: When the underlying cause is treated, the skin signs of AN usually regress. 25 26 Thyroid diseases: Thyroid disease Non-pitting edema, due to GAGs accumulation Generalized myxedema 27 28 7 23/02/2024 Graves Disease: Hyperthyroidism with diffuse goiter, ophthalmopathy, dermopathy Dermopathy: Pretibial myxedema Treatment: steroids Skin changes associated with disorders of the gastrointestinal system and liver Pretibial myxedema: Purple brown plaques on shins 29 30 Zinc deficiency: Acrodermatitis enteropathica is usually seen in neonates either as a genetic condition (defect in zinc transporter proteins) Acquired zinc deficiency: Caused by dietary deficiency (baby who is breastfed from a zinc-deficient mother) or malabsorption (Alcoholism, malabsorption, prolonged parenteral nutrition). Dx: Serum zinc levels will be low. Treatment: Zinc supplementation (1mg/kg/day) should be continued until zinc levels normalize (or lifelong in inherited forms). 31 Zinc deficiency: Clinical features: - Skin changes usually appear within weeks of birth. - Erythematous inflamed scaly skin around the mouth, anus, and eyes (periorificial) as well as acral sites (hands, feet, elbows, and knees) - Patches may be confused with eczema, but this eruption is not itchy, wellat localized sites, and does not respond demarcated to eczema treatment. - If the condition is not recognized and treated promptly then the skin can become crusted, eroded, and secondarily infected (staph, candida) - Babies may become irritable, feed poorly, develop diarrhea, and fail to thrive. 32 8 23/02/2024 Vitamin C deficiency (scurvy): Vitamin C deficiency: Etiologies: Malabsorption Poor diet Elderly Alcoholics Clinical features: Fatigue, weakness. Petechiae, follicular hyperkeratotic papules with perifollicular hemorrhage, usually on the legs, with corkscrew hairs. Bleeding and swollen gums The majority of patients are also anemic (normocytic normochromic). Low ascorbic acid level (zero). Treatment: Vitamin C supplementation of around 1 g is usually needed initially and then 0.5 g daily fora few weeks. 33 Bleeding and swollen hyperplastic gums 34 Pyoderma gangrenosum: Dermatitis herpetiformis: Is a rapid onset painful area of necrotic skin ulceration with characteristic hypertrophic undermined purplish margins. It is a severely intensely itchy, chronic skin disorder. Characterized by erythematous and blistering papules, particularly on the elbows, knees, and buttocks. (extensors) It is usually associated with glutensensitive enteropathy (celiac disease) with some degree of villous atrophy. There is an associated risk of small bowel lymphoma. There is a strong association with ulcerative colitis and Crohn’s disease, rheumatoid arthritis, abnormal gamma globulins, and leukemia. 35 Follicular hyperkeratotic papules with perifollicular hemorrhage, usually on the legs, with corkscrew hairs. 36 9 23/02/2024 Liver diseases: Porphyria cutanea tarda (PCT) Occur secondary to Chronic liver disease. Epidemiology: M>F, genetic predisposition, liver damage (from excessive alcohol intake). Clinical Features: Photosensitivity (face and dorsal hands), bullae, erosions, scarring (milia), and hyperpigmentation in sun-exposed areas. 37 38 Porphyria cutanea tarda (PCT) Pseudoporphyria: § Mimics PCT clinically but no porphyrins are found in urine/blood. § Occurs in patients with chronic renal failure on hemodialysis. § Triggered by a number of medications (NSAIDs, diuretics, antibiotics, and oral contraceptives) and related to underlying liver disease. 39 Xanthomas: Lipid-laden macrophages deposited in the skin. Etiologies: Genetic disease Liver diseases such as primary biliary cirrhosis and Alagille syndrome Hyperlipidemia (either primary or secondary to diabetes, nephrotic syndrome, or hypothyroidism). Diabetes (may be associated with an eruptive type of xanthoma). Soft, yellow, or yellow-orange papules and plaques over the right knee 40 10 23/02/2024 Piebaldism Hypopigmentation: Albinism: AR, congenital loss of skin, eye (e.g. nystagmus), and hair, no pigment production (caused by defective tyrosinase enzymes) Pigmentation disorders Albinism Piebaldism: AD, triangular hypopigmented patches at the forehead and white forelock, disorder of melanocyte development. Vitiligo: Localized depigmentation, sharply demarcated, symmetrical, acquired, destruction of melanocytes. Post-inflammatory: Vitiligo Post-inflammatory E.g. eczema, LP, psoriasis, LE, infections, chemicals, reaction to pigmented nevi, and genetic diseases (e.g. Tuberous sclerosis/ ash leaf spots). 41 42 Vitiligo: Hyperpigmentation: There is wide variation in the pattern of normal pigmentation as a result of hereditary factors and exposure to the sun. Increase in the normal pigment melanin. Acanthosis Nigricans Deposition of bile salts from liver disease, iron salts (hemochromatosis), drugs, or metallic salts from ingestion. Acanthosis Nigricans: is characterized by darkening and thickening of the skin of the axillae, neck, nipples, and umbilicus. Post-inflammatory pigmentation is common, often after acute eczema, fixed drug eruptions, and lichen planus. Areas of lichenification from rubbing the skin are usually darkened. In malabsorption syndromes, pellagra, and scurvy, there is commonly increased skin pigmentation. Hemochromatosis 43 44 11 23/02/2024 Hemochromatosis Skin manifestations of underlying malignancy 45 46 Mycosis fungoides: It is a cutaneous T-cell lymphoma. Initially, well-demarcated erythematous plaques usually develop over the trunk area, which may be mildly pruritic. In some cases, there is a gradual progression to infiltrated lesions, nodules, ulceration, and occasionally erythroderma in Sezary syndrome where there are atypical circulating Sezary cells. 47 48 12 23/02/2024 Poikiloderma: Telangiectasia, reticulate pigmentation, atrophy, and loss of pigment. Etiologies: Idiopathic. May precede mycosis fungoides. Seen after radiotherapy In association with connective tissue diseases e.g.: dermatomyositis. 49 50 Pregnancy dermatosis: Pregnancy dermatosis: 1. Prurigo Gestationis: - Benign, non-specific pruritic papular rash that arises during pregnancy. - It is usually more severe at 1st trimester. 2. Polymorphous eruption of pregnancy (PEP): 3. Pemphigoid Gestationis (PG): - It is a rare disorder that may initially resemble PEP but develops pemphigoid-like vesicles, spreading over the abdomen and thighs. - Involves umbilicus. - PG is an autoimmune disorder. - There is a greater prevalence of premature and smallfor-dates babies and occasional mortality of the fetus. - Recurrence rate high. - It is a pruritic erythematous rash that usually starts in the striae of the abdomen during the third trimester and can become widespread. - Spares umbilicus. - The condition does not affect the baby. - No recurrence. 51 Pregnancy and the skin 52 13 23/02/2024 Thank You 53 54 14