Dermatology Flashcards
What are the 4 differentials of shin lesions
Erythema nodosum
Pretibial myxoedema
Pyoderma gangrenosum
Necrobiosis lipoidica diabeticorum
Give two skin reactions associated with inflammatory bowel disease
Pyoderma gangrenosum
Erythema nodosum
List some causes of erythema nodosum
streptococcal infections, sarcoidosis, IBD, drugs (penicillins, sulphonamides, OCP)
What antibodies are seen in pemphigus vulgaris?
Desmoglein antibodies
What is the treatment for rosacea?
Mild/mod: topical metronidazole
Severe: oral tetracycline
Give two conditions associated with seborrheic dermatitis
HIV
Parkinsons disease
Give two conditions associated with malassazia furfur
Seborrheic dermatitis
ptitiryasis versicolor
What malignancy is associated with acanthosis nigricans?
gastrointestinal adenocarcinoma / gastric cancer
What is pretibial myxoedema associated with?
Hyperthyroid (despite the name)
What does immunofluorescence show in bullous pemphigoid?
immunofluorescence shows IgG and C3 at the dermoepidermal junction
What antibodies are seen in bullous pemphigoig?
Hemidescmosomal BP antigens
Commonest cause of Erythema multiforme
HSV
How does systemic mastocytosis present? What do you look for in the urine + serum?
(Neoplastic proliferation of mast cells)
Presentation: urticaria pigmentosa - produces a wheal on rubbing (Darier's sign) flushing abdominal pain monocytosis on the blood film
Ix:
Urinary histamine
Raised serum triptase
Acitinic keratosis treatment
flurouracil
Treatment of keloid scars
intra-lesional steroids e.g. triamcinolone
Removal
What causes pallegra? Clinical features?
nicotinic acid (niacin) deficiency (e.g. in isoniazid therapy)
D's: dermatitis (brown scaly rash on sun-exposed sites - termed Casal's necklace if around neck) diarrhoea dementia, depression death if not treated
What paraneoplastic skin condition is related to gastric cancer?
nigricans acanthosis
What paraneoplastic skin condition is related to lymphoma?
Erythroderma
What paraneoplastic skin condition is related to lung cancer?
Dermatomyositis
Erythema gyratum repens (wood grain appearance)
First line hyperhydrosis
topical aluminium chloride
What drugs exacerbate plaque psoriasis?
beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
What might trigger guttate psoriasis?
Streptococcal infection
Organism that causes erisepylas?
Group A strep
Causes of tinea capitis
Trichophyton tonsuras or M. canis
Causes alopecia
Green-blue in fluorescent light
