Passmed Derm Flashcards

1
Q

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

A

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

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2
Q

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
A

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.

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3
Q

Compare superficial spreading and nodular melanoma

A

Superficial
-Most common
Younger people
-Apperance - A growing mole

Nodular

  • Middle aged
  • Red or black lump or lump which bleeds or oozes
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4
Q

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

A

pyoderma gangrenosum

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5
Q

Erythema nodosum
How does it present?
Usual causes?

A

symmetrical, erythematous, tender, nodules which heal without scarring

Strep, sarcoid, IBD, Drugs Eg penicillin /COCP

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6
Q

Pretibial myxoedema

Seen when? Presents how?

A

Graves

shiny, orange peel skin - symmetrical and erythematous

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7
Q

How does pyoderma gangrenosum present?

A

initially small red papule

later deep, red, necrotic ulcers

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8
Q

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?

A

Seborrhoeic keratoses

reassurance about the benign nature

curettage / cryosurgery

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9
Q

Who is affected by Acral lentiginous melanoma ?

Where?

A

Commonest in people with dark skin

enlarging discoloured skin patch on the palms, fingers, soles or toes

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10
Q

What is due to over exposure by infrared radiation Eg Hot water bottle on back?

A

Erythema ab igne

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11
Q

Key Ix in someone presenting with erythema nodosum?

A

CXR

  • exclude Sarcoidosis and TB which are causes
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12
Q

Features of pityruasis rosea ? mx?

A

Initial Herald patch
-> erythematous, OVAL, scaly patches

Self limiting 4-12 weeks

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13
Q

itchy papules on chest and back

nail dystrophy

A

Darier’s disease

[keratosis follicularis]

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14
Q

itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks)? Ix?

A

Dermatitis hepetiformis Skin biopsy - IgA on immunofluorescence

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15
Q

Pyoderma gangrenosum 2 Associations?

Mx?

A
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

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16
Q

Keratoacanthoma appearance?

Need to do what?

A

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

17
Q

Cause of 90% of fungal nail

A

Trichophyton rubrum

18
Q

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?

A

Milia

19
Q

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.

A

Acanthosis nigricans

may be associated with GI malignancies such as gastric and pancreatic cancer.

20
Q

What can cause patchy areas of depigmentation in pts with darker skin

A

topical corticosteroids

21
Q

1st line Ix in allergic dermatitis

A

Patch testing

22
Q

Uses of:

Skin prick test

RAST test

Skin patch test

A

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

23
Q

pemphigus vs pemphigoid mucosal involvement

A

mucosal involvement: pemphigus vulgaris

24
Q

screen for patients who are at risk of developing pressure areas

A

Waterlow score

25
Q

When can kids go back to school with impetigo

A

When no longer contagious

  • all lesions have crusted over
  • Or 48h after treatment starts
26
Q

brown, velvety patches which affect the axilla, neck and groin.

2 causes

A

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