Derm Flashcards
Livedo reticularis - capillary dilation with stagnation of blood. Mottled skin discolouration on central areas, legs, arms, trunk in cold weather. Causes include
Antiphospholipid syndrome
Thrombocytosis (high plts)
Vasculitis
Hyperviscosity
Erythema multiforme - annular, target lesions that may develop into target lesions. Causes include
Idiopathic (50%) Infection (mycoplasma pneumonia, HSV, EBV) Vasculitis (SLE) Carcinoma Sarcoidosis Pregnancy Drugs
Severe form of erythema multiforme is called
Steven Johnsons syndrome
Lupus vulgaris - ‘apple jelly’ brown firm translucent nodules. Present in…
TB
Cutaneous infection with deep involvement. Skin is erythematous, raised, hot and tender with poorly demarcated edges. Pyrexia and WCC are also present. What is the likely diagnosis?
Cellulitis
Commonest causes - Staph aureus and strep pyogenes
Nicotinic acid deficiency causes
Pellagra
Lupus pernio - chronic plaques. Blue-red nodular lesions on the nose and hands, present in…
Sarcoidosis
Pyoderma gangrenosum - indolent boils that rapidly expand, break down and leave large ulcerated painful areas with an undertermined edge. ±pyrexia and malaise. Present in…
Chronic inflammation
UC
Crohn’s
RhA
Cafe au lait spots - macular hyperpigmentation. Present in
Neurofibromatosis (type 1)
Well-defined silvery scales and plaques, usually on extensor surfaces of elbows, knees, scalp and sacrum. What is the likely diagnosis?
Psoriasis
also nail changes, Kobner phenomenon, Auspitz sign, arthritis
Causes of acanthosis nigricans
Gastric carcinoma Hodgkin's lymphoma Obesity Insulin resistance (DM) Acromegaly Thyroid disease
Squamous cell carcinoma are usually in areas of sun-damaged skin. Preceded by acitinic keratosis (scaly and erythematous). Where are lesions commonly and what do they look like?
Back of hands, face, trunk.
Hyperkeratotic, ulcerated (can be deep), expanding nodules with everted edges
Keratoacanthomas can look like SCC. They can be distinguished since…
they will rapidly grow and self-heal
leaves pitting scar
A 41 year old woman has a painless fluctuant swelling in her right supraclavicular fossa. It becomes inflamed at times + she has expressed thick, foul-smelling white matter from it. What is the likely diagnosis?
Sebaceous cyst
A 25 year old man with a history of diarrhoea & abdominal pain has a blistering rash on his buttocks + elbows with marked pruritus. Anti- endomysial antibodies are positive. What is this lesion called?
Dermatitis herpetiformis
Presents in coeliac disease
A 40 year old man with joint pains was noted to have nail pitting plus sublingual hyperkeratosis. He also had a rash on the scalp margin. What is the likely diagnosis?
Psoriasis
A 70 year old man under investigation for a chronic cough, weight loss + haemoptysis developed left sided chest pain followed by an area of erythema & grouped vesicles. What is the likely diagnosis?
Shingles
Reactivation of VZV
A 70 year old man with a popular lesion in the left temporal area. The lesion is small + glistening with a central necrotic area. What is the likely diagnosis?
Basal cell carcinoma
A 40 year old lady noticed that a mole on her neck has increased in size, became darker in colour + started to itch. The border + edge of the mole is irregular + it has bled on a number of occasions. What is the likely diagnosis?
Malignant melanoma
A 20 year old man with a rash on both elbows. The rash consists of well defined erythematous plaques with adherent silvery scales. What is the likely diagnosis?
Psoriasis
= this type of discoid/nummular psoriasis. Less scaly plaques in axilla, groin regions = flexural psoriasis.
Guttate psoriasis
Common in children
Reactive, triggered by Group A strep infection normally
Small, numerous teardrop shapes on trunk
Erythema marginatum is part of…
5 major criteria of acute rheumatic fever
n.b. other criteria = arthritis, carditis, chorea, subcutaenous nodules
A 22 year old man presents with a lump on the scalp. O/E: smooth, spherical, tense lump. A small punctum can be seen on the surface. What is the likely diagnosis?
Sebaceous cyst
Can occur anywhere where there are sebaceous glands. There are none on the palms of the hand and soles of feet. Scalp is a commonly affected area. Punctum is visible on the surface of the lump and is diagnostic of a sebaceous cyst.
Mycosis fungoides is a skin rash associated with….
Non-hodgkin’s lymphoma may be associated with these well-defined indurated scaly plaque-like lesions with raised ulcerated nodules caused by cutaneous T-cell lymphoma.
±Sezary’s syndrome, painless rubbery lymphadenopathy, hepatosplenomegaly, abdominal mass
Erythroderma (chronic inflammatory skin condition with scaling in >50% of total body) is associated with which cutaneous malignancy
T-cell lymphoma
Types of basal cell carcinoma
Nodulo-ulcerative (most common)
Morphoeic
Superficial
Pigmented
Steven Johnson’s syndrome is characterised by
Affects >2 mucous membranes
Systemic symptoms
Shock (hypotension + tachy)
Generalised pustular psoriasis
Pustules over limbs + torso
Associated with hypoparathyroidism
Palmoplantar psoriasis
RFs: smoking, AI thyroid disease, middle-aged women
Erythematous plaques with pustules on palms and soles
Part of SAPHO mnemonic
SAPHO associated with a type of psoriasis stands for….
Synovitis Acne Palmoplantar pustulosis Hyperostosis (seen on XR) Osteitis
Nail signs in psoriasis
Onycholysis
Pitting
Subungual hyperkeratosis
