Body Dysmorphic Disorder — SCE Dermatology MCQ

Correct answer: B — Body dysmorphic disorder

The correct answer is B, Body dysmorphic disorder. This woman shows the hallmark features of BDD: preoccupation with a perceived appearance flaw (facial redness) that is disproportionate to objective findings (minimal physiological erythema on examination), combined with compulsive checking behaviours (hours of mirror and magnifying-light scrutiny) and social avoidance driven by shame about the perceived defect. NICE guidance describes BDD as characterised by time consuming behaviours such as mirror gazing and excessive checking, occurring alongside a preoccupation with an imagined or grossly exaggerated defect in appearance. The marked mismatch between subjective distress and objective clinical signs, plus the ritualistic checking, is the key discriminator that separates BDD from a primary dermatological diagnosis. Why the other options are wrong: A. Carcinoid syndrome: causes episodic flushing associated with diarrhoea, wheeze and abdominal pain due to vasoactive mediator release from a neuroendocrine tumour, not a fixed perceived redness with normal skin examination. E. Steroid-induced rosacea: requires a history of prolonged topical or systemic corticosteroid use with rebound erythema and papules on withdrawal; there is no such exposure history here and examination is essentially normal. D. Rosacea: would show objective persistent central facial erythema, telangiectasia or papulopustules on examination; here findings are minimal, arguing against a true dermatological process. C. Social anxiety disorder: avoidance is driven by fear of negative evaluation in social situations generally, not by fixation on a specific perceived physical defect with repetitive mirror checking, which is specific to BDD. Key point: A striking mismatch between a patient's fixed belief in visible facial redness and near-normal examination findings, with compulsive mirror checking and avoidance, points to body dysmorphic disorder rather than a primary skin disease.

Reference: NICE Clinical Guideline CG31: Obsessive-compulsive disorder and body dysmorphic disorder: treatment, Context section (2005, updated) - https://www.nice.org.uk/guidance/cg31/chapter/Context