Androgenetic alopecia — SCE Dermatology MCQ

Correct answer: D — Female-pattern hair loss

The correct answer is D, female-pattern hair loss. This is characterised by gradual, non-scarring thinning that predominates over the crown and vertex with relative preservation of the frontal hairline, exactly as described in this 32-year-old woman with a 3 year history. Dermoscopy showing follicular miniaturisation (increased hair diameter diversity) is the key diagnostic sign, reflecting progressive conversion of terminal to vellus-like hairs under androgen influence at the follicular level, even when serum androgens and thyroid function are normal. Normal ferritin and thyroid function help exclude reversible causes of diffuse shedding, and the absence of scale or scarring excludes inflammatory and scarring alopecias, leaving female-pattern hair loss as the diagnosis that fits the pattern, chronicity and trichoscopic findings. Why the other options are wrong: E. Chronic telogen effluvium: causes diffuse, generalised shedding across the whole scalp rather than a patterned crown predominance, and does not produce follicular miniaturisation on dermoscopy. B. Frontal fibrosing alopecia: this is a scarring alopecia primarily affecting the frontotemporal hairline, causing recession and loss of follicular openings, which contradicts the preserved frontal hairline and non-scarring nature here. C. Diffuse alopecia areata: presents with sudden-onset patchy or diffuse hair loss, often with exclamation mark hairs, yellow dots or black dots on dermoscopy, not the gradual miniaturisation pattern described. A. Tinea capitis: is an infective, usually scaly and sometimes inflammatory or pustular scalp condition, typically in children, which is excluded by the absence of scale here. Key point: crown-predominant, non-scarring thinning with a preserved frontal hairline and follicular miniaturisation on trichoscopy, in a woman with normal ferritin, thyroid and androgen levels, defines female-pattern hair loss.

Reference: NICE Clinical Knowledge Summaries: Female pattern hair loss (female androgenetic alopecia), https://cks.nice.org.uk/topics/female-pattern-hair-loss-female-androgenetic-alopecia/