Miniaturized hairs in Alopecia Areata

Alopecia Areata: One of Many Causes of Alopecia Areata

Miniaturization of hairs is a feature of alopecia areata. Regrowing hairs in alopecia areata are often thinner as they struggle to figure out how to do the job they once did. It’s important not to jump to conclusions too quickly when one sees miniaturized hairs especially the conclusion that “miniaturization equates to a diagnosis is androgenetic alopecia”.

In this image, black dots (star) and exclamation mark hairs (arrow) are clues that the diagnosis is alopecia areata and the miniaturized hairs are part of alopecia areata.

Miniaturized regrowing hairs can be seen throughout this image. Black dots and exclamation mark hairs are also seen and help confirm a diagnosis of alopecia areata

It can be challenging to know if the patient also has a diagnosis of androgenetic alopecia too and in some cases I will defer a final confirmation of a possible diagnosis of androgenetic alopecia until I see the scalp again in 3-6 months and see what happens to the miniaturized hairs. Miniaturized hairs in alopecia areata can thicken up very quickly and fully in a few months when the right treatment is on board. In androgenetic alopecia miniaturized hairs may thicken up slightly (and often not fully) if the right treatment is present but it may take 6-9 months to convincingly do so.

Causes of Miniaturization

Causes of miniaturization include triangular alopecia, discoid lupus, systemic lupus, alopecia areata, dissecting cellulitis, central centrifugal cicatricial alopecia, traction alopecia, psoriasis, chemotherapy induced alopecia, psorasiform drug reactions, and secondary syphilis.