Dermatology Flashcards
shin lesion DD
erythema nodosum, pretibial myxoedema, pyoderma gangrenosum, necrobiosis lipoidica diabeticorum
erythema nodosum features
symmetrical, erythematous, tender, nodules that heal w/o scarring
most common causes of erythema nodosum
strep, sarcoidosis, IBD, iatrogenic (penicillins, sulphonamides, OCP)
pretibial myxoedema features
symmetrical, erythematous lesions, shiny, orange peel skin
pretibial myxoedema is seen in
Grave’s DZ
pyoderma gangrenosum
initially: small red papule, later: deep, red, necrotic ulcer, violaceous border
most common causes of pyoderma gangrenosum
idiopathic
pyoderma gangrenosum is associated with
IBD, CT DZ, myeloproliferative disorders
necrobiosis lipoidica diabeticorum
shiny, painless, yellow/red skin, shins, DM
necrobiosis lipoidica diabeticorum often associated with
telangectasia
symmetrical, erythematous, tender, nodules that heal w/o scarring are features of
erythema nodosum
strep, sarcoidosis, IBD, iatrogenic (penicillins, sulphonamides, OCP) are causes of
erythema nodosum
symmetrical, erythematous lesions, shiny, orange peel skin are features of
pretibial myxoedema
Skin manifestation of Grave’s DZ
pretibial myxoedema
initially: small red papule, later: deep, red, necrotic ulcer, violaceous border are features of
pyoderma gangrenosum
shiny, painless, yellow/red skin, shins, DM are features of
necrobiosis lipoidica diabeticorum
types of hypersensitivity reaction
I = anaphylactic, II = cell bound, III = immune complex, IV = delayed hypersensitivity
type I hypersensitivity reaction examples
anaphylaxis, atopy (eczema, asthma, hay fever)
type II hypersensitivity reaction examples
AI haemolytic anaemia, ITP, Goodpasture’s S, pernicious anaemia, acute haemolytic transfusion reactions, rheumatic fever, pemphigus vulgaris/bullous pemphigoid
type III hypersensitivity reaction examples
serum sickness, SLE, PSGN, extrinsic allergic alveolitis (especially acute phase)
type IV hypersensitivity reaction examples
TB, tuberculin skin reaction, GVHD, allergic contact dermatitis, scabies, extrinsic allergiv alveolitis (esp chronic phase), MS, GBS
type V hypersensitivity reaction examples
Graves’, MG
anaphylaxis, atopy (eczema, asthma, hay fever) are examples of
type I hypersensitivity reaction
AI haemolytic anaemia, ITP, Goodpasture’s S, pernicious anaemia, acute haemolytic transfusion reactions, rheumatic fever, pemphigus vulgaris/bullous pemphigoid are examples of
type II hypersensitivity reactions
serum sickness, SLE, PSGN, extrinsic allergic alveolitis (especially acute phase) are examples of
type III hypersensitivity reaction
TB, tuberculin skin reaction, GVHD, allergic contact dermatitis, scabies, extrinsic allergiv alveolitis (esp chronic phase), MS, GBS are examples of
type IV hypersensitivity reaction
Graves’, MG are examples of
type V hypersensitivity reaction
eczema herpeticum management
admission, IV acyclovir (potentially life threatening)
lichen planus features
itchy, papular, palms, soles, genitalia, flexor surfaces, white lace pattern (Wickham’s striae), Koebner phenomenon, oral involvement, thinning of nail plate, longitudinal ridges
causes of lichenoid drug eruptions
gold, quinine, thiazides
management of lichen planus
topical steroids, PO steroids/immunosuppression if extensive
itchy, papular, palms, soles, genitalia, flexor surfaces, Wickham’s striae, Koebner phenomenon, oral involvement, thinning of nail plate, longitudinal ridges are features of
lichen planus
gold, quinine, thiazides can cause
lichenoid drug erruption
mycosis fungoides is
a rare form of T-cell lymphoma that affects the skin
mycosis fungoides features
itchy, red patches, differing colours
mycosis fungoides is easily confused with
eczema/psoriasis
a rare form of T-cell lymphoma that affects the skin
mycosis fungoides
itchy, red patches, differing colours, easily confused with eczema/psoriasis
mycosis fungoides
exacerbating factors for psoriasis
trauma, alcohol, drugs (B-blockers, Li, antimalarials (chloroquine, hydroxychloroquine), NSAIDs, ACEi, infliximab), withdrawal of systemicsteroids
guttate psoriasis may be triggered by
strep infection
acanthosis nigricans features
symmetrical, brown, velvety plaques, neck, axilla, groin
causes of acanthosis nigricans
GI ca, DM, obesity, PCOS, acromegaly, Cushing’s DZ, hypothyroidism, FH, Prada-Willi S, OCP, nicotinic acid
symmetrical, brown, velvety plaques, neck, axilla, groin are features of
acanthosis nigricans
GI ca, DM, obesity, PCOS, acromegaly, Cushing’s DZ, hypothyroidism, FH, Prada-Willi S, OCP, nicotinic acid may be causes of
acanthosis nigricans
pemphigus vulgaris is
an AI DZ, common in the Ashkenazi Jewish populaiton
pemphigus vulgaris features
mucosal ulceration, skin blistering, flaccid, easy rupturing, vesicles, bullae, Nikolsky’s sign
management of pemphigus vulgaris
steroids, immunosuppression
an AI DZ, common in the Ashkenazi Jewish populaiton describes
pemphigus vulgaris
mucosal ulceration, skin blistering, flaccid, easy rupturing, vesicles, bullae, Nikolsky’s sign are features of
pemphigus vulgaris
erythema multiforme features
target lesions, backs of hands/feet, spreads to torso, upper limbs > lower limbs, mild pruitis
causes of erythema multiforme
HSV, idiopathic, mycoplasma, strep, drugs (penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, OCP, nevirapine), SLE, sarcoidosis, ca
erythema multiforme major vs minor
major involves the mucous membranes
target lesions, backs of hands/feet, spreads to torso, upper limbs > lower limbs, mild pruitis are features of
erythema multiforme
HSV, idiopathic, mycoplasma, strep, drugs (penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, OCP, nevirapine), SLE, sarcoidosis, ca are causes of
erythema multiforme
