Alopecia Areata Incognita: Current Evidence

Area of Science:

• Dermatology
• Trichology
• Hair Loss Disorders

Background:

• Alopecia areata incognita (AAI) is an underdiagnosed subtype of alopecia areata (AA) with significant hair shedding and diffuse thinning.
• First described in 1987, AAI lacks extensive published reports and standardized diagnostic criteria.
• This review consolidates current evidence on AAI, including its pathogenesis, clinical and diagnostic features, and treatments.

Purpose of the Study:

• To provide a comprehensive review of alopecia areata incognita (AAI).
• To consolidate current evidence on AAI pathogenesis, clinical presentation, diagnostic methods, and treatments.
• To highlight the need for further research to establish diagnostic criteria and treatment protocols.

Main Methods:

• A systematic literature search was conducted using PubMed.
• All articles discussing alopecia areata incognita (AAI) published up to September 2024 were identified.
• The review included 28 articles covering epidemiology, pathogenesis, clinical presentation, trichoscopy, histopathology, diagnosis, and treatment.

Main Results:

• Alopecia areata incognita (AAI) presents with acute onset and sudden diffuse hair loss, resembling telogen effluvium (TE) and potentially associated with androgenetic alopecia (AGA).
• Diagnostic challenges exist, but a combination of clinical, trichoscopic, and histopathologic evaluations aids in accurate identification.
• AAI generally shows a favorable response to topical steroids, indicating a better prognosis compared to other AA subtypes.

Conclusions:

• Alopecia areata incognita (AAI) is a distinct entity within the alopecia areata spectrum.
• Accurate diagnosis requires integrated clinical, trichoscopic, and histopathologic assessments.
• Further robust studies are essential for establishing definitive diagnostic criteria and treatment guidelines for AAI.