inflammatory skin conditions Flashcards
What is pemphigus vulgaris?
autoimmune disorder caused by autoantibodies to desmosome adhesion molecules in the epidermis (desmosomes, which connect epithelial skin cells side to side). pts usually middle aged or elderly, and they present with painful, fragile blisters in the oropharynx and on the chest, face, and perineal regions
What are the biopsy findings seen in pemphigus vulgaris?
separationof epidermal cells (acantholysis) with intact basement membrane. immunofluorescence shows antiepidermal antibodies.
What is the treatment and complications of pemphigus vulgaris?
steroids, azathiprine, cyclophosphamide. may cause sepsis, high mortality if untreated, osteoporosis if chronic steroid use
What is bullous pemphigoid?
autoimmune DO caused by autoantibodies to the hemidesmosomes of the epidermal basement membrane. most pts > 60 yo. patitents present with widespread blistering, esp. of flexor surfaces and perineal region. blisters are fragile
treatment of bullous pemphigoid
oral or topical steroids or azathioprine
What causes porphyria cutanea tarda (risk factors and pathophysiologically)
- deficiency of hepatic uroporphyrinogen decarboxylase
- risks: alcoholism, hep C, iron overload, estrogens, smoking
What are the clinical manifestations of porphyria cutanea tarda?
chronic blistering lesions on sun-exposed skin, hyperpigmented skin, facial hypertrichosis (too much hair). ruptured blisters may scar
What are the labs that suggest porphyria cutanea tarda?
high AST, ALT, incr. total plasma porphyrin, incr urine porphyrins, decr. uroporphyringoen decarboxylase
What is the tx for porphyria cutanea tarda?
phelbotomy, low dose chloroquine or hydroxychloroquine, sunscreen, avoid triggers
What exposures most often cause erythema multiforme and what does this reaction look like?
may be caused by NSAIDs, penicillins, sulfonamides, OCPs, and anticonvulsants, mycoplasma pneumoniae and HSV. look like target lesions, macules, plaques, or vesicles also seen. may be on palms and soles
What is the difference between Stevens-Johnson syndrome and toxic epidermal necrolysis?
amount of body surface area involved:
-30%: TEN
What is seborrheic dermatitis?
chronic hyperproliferation of the scalp or face. will be pruritic with erythematous plaques with yellow greasy scales
What is the treatment for seborrheic dermatitis?
shampoo with selenium tar or ketoconazole when the scalp is involved; topical steroids or antifungals in other regions
What are the biopsy findings of psoriasis?
thickened epidermis, absent granular cell layer, and nucleated cells in the stratum corneum. incr ESR
What is erythema nodosum?
inflammation of the subcutaneous fat septa that results in painful erythematous nodules; most common on the anterior tibia but also affects the trunk and other extremities
What are the underlying conditions associated with erythema nodosum?
delayed immunologic rxn to infection, collagen vascular disease, IBD, or drugs
