Dermatology Flashcards
erythema nodosum
painful blue-red lesions on the anterior shin
seen in sarcoidosis, TB, Crohn’s and leprosy
erythema multiforme
“target” lesions with central blisters
due to an autoimmune reaction to medications, infection, cancers (can be idiopathic)
erythema ab igne
brown-y discolouration due to heat/ intra-red exposure (often seen in pts with abdo pain that use hot water bottles)
can go on to develop SCC
dermatitis herpetiformis
autoimmune blistering due to IgA deposits in the dermis on the extensor surfaces
seen in coeliac disease
lichen’s sclerosis
inflammatory condition that usually affects the genitals
in females is very itchy and can increase risk of vulval cancer (give topical steroids and emollients)
in males occurs in uncircumcised, results in phimosis with a white ring around it
lichen’s planus
autoimmune inflammatory condition
purple, polygonal papules, pruritic (itchy)
saw tooth T-cell infiltration between dermis and epidermis
is associated with hepatitis C
acanthosis nigricans
symmetrical velvety brown plaques around body creases
due to insulin resistance (so seen in T2DM, Cushing’s, PCOS, Acromegaly, etc)
pityriasis rosea
acute self limiting rash often following a viral infection
begins with a herald patch then the rash develops to form a ‘Christmas tree’ distribution
strawberry haemangioma
AV malformation in new-born, will regress
cherry haemangioma
AV malformation that occurs with age, is benign, will not regress
hereditary haemorrhagic telangiectasia
aka Osler-Weber-Rendu syndrome
is autosomal dominant
causes multiple telangiectasia over skin and mucosa
malignant melanoma
Asymmetric Border is irregular Colours (2 or more) Diameter (often >6mm) Evolution of lesion
requires excision biopsy with margin
70% of cases are superficial spreading melanoma, nodular melanoma is the most aggressive type
squamous cell carcinoma of the skin
sun exposure
actinic keratoses is the premalignant version
immunosuppression, Marjolin’s ulcer, smoking, etc are risk factors
surgical excision with margin 4mm if <20mm or 6mm margin if >20mm
basal cell carcinoma
most common cancer in the western world
slow growth and local invasion of a lesion on sunexposed sites - may ulcerate to leave a central crater
surgical removal, curettage, cryotherapy, topical fluorouracil and radiotherapy
impetigo
superficial skin infection caused by staph aureus or strep pyrogenes
commonly in children on their faces
very contagious, golden crusted skin lesions (incubation period 4-10days)
Rx: topical fusidic acid, if extensive oral flucloxacillin
should be excluded from school until non-contagious ie 48hrs after starting treatment or when scabs have crusted over
cellulitis
due to strep pyrogenes or staph aureus
Eron classification
mild-moderate: flucloxacillin +/- clindamycin
severe: IV benzylpenicillin and flucloxacillin