Alopecia and hair disorders in children — formative SAQs

SAQ 1 — The smooth bald patch (10 marks, 15 minutes)

An eight-year-old girl is brought by her mother, who has noticed a coin-sized, completely bald, smooth patch behind the left ear over three weeks. The overlying skin is normal with no scale or redness, and at the edge there are a few short hairs that taper to a fine point. Dermoscopy shows yellow dots, black dots and exclamation-mark hairs. There is no lymphadenopathy. [1]

a) What is the most likely diagnosis, and which single bedside feature most reliably distinguishes it from tinea capitis? (2 marks) [12]

b) Name the key autoimmune association and the screening test you would perform. (2 marks) [4]

c) Outline the stepwise management for limited patchy disease, naming the first-line topical agents and giving the intralesional triamcinolone acetonide concentration and dosing interval you would use for a discrete patch. (4 marks) [1] [2]

d) List four clinical features that predict a poorer prognosis. (2 marks) [4]

SAQ 2 — The irregular patch on a normal scalp (10 marks, 15 minutes)

A twelve-year-old boy has an odd, irregular area of thinned hair over the crown. The hairs are broken to wildly varying lengths, the scalp beneath is completely normal with no scale, and there is no lymphadenopathy. He denies pulling at the hair. He has recently become more anxious. [8]

a) What is the most likely diagnosis, and which two features on examination and dermoscopy separate it from alopecia areata? (3 marks) [12]

b) State the first-line treatment and explain why pharmacotherapy is not first-line, citing the evidence. (3 marks) [8] [9]

c) Name a specific and potentially serious complication of this condition that you should ask about in the history, and how it may present. (2 marks) [8]

d) Briefly contrast this with diffuse generalised shedding beginning two months after a febrile illness: name the diagnosis, the bedside test that confirms active shedding, and the principle of management. (2 marks) [12]