Passmed Derm Flashcards
A 38-year-old man presents with a sudden onset rash. He is otherwise well in himself and has no notable past medical history. You see from his notes he has had recent tonsillitis for which he received amoxicillin. On examination, there are multiple papules on his trunk and proximal extremities. There is a fine scale on several of these lesions. What is the most likely diagnosis?
Drug eruption
Pityriasis Rosea
Guttate psoriasis
Nummular dermatitis
Guttate
Children and adolescents. It may be precipitated by a streptococcal infection 2-4 weeks prior to the lesions appearing
Tear drop lesions on trunk and limbs
56-year-old gentleman presents to the dermatology clinic. Over the last few weeks, he has noticed a new, enlarging lesion on his cheek which sometimes bleeds. On examination, he has Fitzpatrick skin type I, multiple melanocytic naevi over his body, and the lesion in question is a large, black, dome-shaped lump, of 1cm diameter, located on his right cheek. What is this lesion most likely to represent?
Nodular melanoma BCC SCC Lentigo melanoma Superficial spreading melanoma
Nodular
tends to affect people over the age of 50, with fairer skin, and to occur in chronically sun-exposed areas
The lump may be ulcerated, bleeding, itch or sting and may have a smooth, crusty, rough or warty surface.
Compare superficial spreading and nodular melanoma
Superficial
-Most common
Younger people
-Apperance - A growing mole
Nodular
- Middle aged
- Red or black lump or lump which bleeds or oozes
A 62-year-old female is referred to dermatology by her GP due to a lesion over her shin. It initially started as a small red papule which later became a deep, red, necrotic ulcer with a violaceous border. What is the likely diagnosis?
erythema nodosum
pretibial myxoedema
pyoderma gangrenosum
necrobiosis lipoidica diabeticorum
pyoderma gangrenosum
Erythema nodosum
How does it present?
Usual causes?
symmetrical, erythematous, tender, nodules which heal without scarring
Strep, sarcoid, IBD, Drugs Eg penicillin /COCP
Pretibial myxoedema
Seen when? Presents how?
Graves
shiny, orange peel skin - symmetrical and erythematous
How does pyoderma gangrenosum present?
initially small red papule
later deep, red, necrotic ulcers
What is this describing?
large variation in colour from flesh to light-brown to black
have a ‘stuck-on’ appearance
keratotic plugs may be seen on the surface
mx?
Seborrhoeic keratoses
reassurance about the benign nature
curettage / cryosurgery
Who is affected by Acral lentiginous melanoma ?
Where?
Commonest in people with dark skin
enlarging discoloured skin patch on the palms, fingers, soles or toes
What is due to over exposure by infrared radiation Eg Hot water bottle on back?
Erythema ab igne
Key Ix in someone presenting with erythema nodosum?
CXR
- exclude Sarcoidosis and TB which are causes
Features of pityruasis rosea ? mx?
Initial Herald patch
-> erythematous, OVAL, scaly patches
Self limiting 4-12 weeks
itchy papules on chest and back
nail dystrophy
Darier’s disease
[keratosis follicularis]
itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks)? Ix?
Dermatitis hepetiformis Skin biopsy - IgA on immunofluorescence
Pyoderma gangrenosum 2 Associations?
Mx?
Idiopathic in 50% inflammatory bowel disease: ulcerative colitis, Crohn's rheumatoid arthritis, SLE myeloproliferative disorders lymphoma, myeloid leukaemias monoclonal gammopathy (IgA) primary biliary cirrhosis
Oral steroids
-> ciclosporin / infliximab
Keratoacanthoma appearance?
Need to do what?
volvano / crater
initially a smooth dome-shaped papule
rapidly grows to become a crater centrally-filled with keratin
Excised as hard to clinically differentiate between SCC - also limits scarring
Cause of 90% of fungal nail
Trichophyton rubrum
A neonate is brought to your surgery because his mother has noticed some skin lesions on his face. On examination there are multiple tiny white papules on the nose. What is the most likely diagnosis?
Milia
72-year-old man is investigated for weight loss. On examination he is deeply jaundiced and cachectic. He also has a dark velvety lesion coating his tongue.
Acanthosis nigricans
may be associated with GI malignancies such as gastric and pancreatic cancer.
What can cause patchy areas of depigmentation in pts with darker skin
topical corticosteroids
1st line Ix in allergic dermatitis
Patch testing
Uses of:
Skin prick test
RAST test
Skin patch test
Skin prick test
- food allergies and also pollen
RAST test
- food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom
- [Blood tests may be used when skin prick tests are not suitable, for example if there is extensive eczema or if the patient is taking antihistamines]
Skin patch test
-contact dermatitis
pemphigus vs pemphigoid mucosal involvement
mucosal involvement: pemphigus vulgaris
screen for patients who are at risk of developing pressure areas
Waterlow score
When can kids go back to school with impetigo
When no longer contagious
- all lesions have crusted over
- Or 48h after treatment starts
brown, velvety patches which affect the axilla, neck and groin.
2 causes
Acanthosis nigricans
gastrointestinal cancer diabetes mellitus obesity polycystic ovarian syndrome acromegaly Cushing's disease hypothyroidism familial Prader-Willi syndrome drugs: oral contraceptive pill, nicotinic acid
