Alopecia areata in Adult
Alopecia areata is seen equally in both sexes and in patients of all ages and races and ethnicities. There is an increased incidence of alopecia areata in patients with Down syndrome as well as those with autoimmune diseases, most commonly thyroid disease. Patients with alopecia areata are also more likely to have atopy, and its presence is felt to be a poor prognostic indicator.
While medication-induced alopecia areata has been uncommon in the literature, there have been articles published reporting an association with some medications, including the TNF inhibitors adalimumab, etanercept, and infliximab. Other more recently described culprit agents include proton pump inhibitors and immune checkpoint inhibitors (CTLA-4, PD-1) that are used to treat malignancies.
The course of alopecia areata is unpredictable, with wide variation in duration and extent of disease occurring from patient to patient. In most patients, hair will eventually spontaneously regrow, although recurrences are common. The condition is treatable but cannot be cured.
In one retrospective study of 321 patients, temporal area involvement was independently associated with worse prognosis (in addition to extent of hair loss).
A 2022 retrospective population-based study in Taiwan showed an increase in retinal diseases among 9909 patients with alopecia areata. The disease extent and prior steroid treatment were not commented on; further studies are needed to confirm an association.
L63.9 – Alopecia areata, unspecified
68225006 – Alopecia areata
Differential Diagnosis & Pitfalls
- Trichotillomania, from the twisting and pulling of hair, may mimic alopecia areata. Hairs are broken off at varying lengths.
- Telogen effluvium from nutritional, hormonal, and drug etiologies can lead to large clumps of hair loss in a similar fashion to alopecia areata. The loss is diffuse, not localized.
- Tinea capitis has hair loss accompanied by scale and inflammation.
- Secondary syphilis can result in diffuse patchy alopecia.
- Androgenetic alopecia – male or female pattern
Drug Reaction Data