Title : An analysis of alopecia areata incognita following mRNA COVID-19 vaccination in perimenopausal women
Abstract:
Alopecia areata incognita (AAI), a rare and often underrecognized variant of alopecia areata, presents as diffuse, acute-onset telogen hair shedding without the classic well-demarcated patches of hair loss. The pathogenesis of AAI is thought to involve autoimmune targeting of anagen hair follicles, leading to premature follicular regression and abrupt telogen effluvium (TE). Case reports and observational data have identified a temporal association between mRNA COVID-19 vaccination and the onset of alopecia areata spectrum disorders, including AAI, particularly in perimenopausal women. Immunologic shifts during the perimenopausal transition, including estrogen fluctuations, declining immune regulation, and increased predisposition to autoimmunity, may amplify susceptibility to vaccine-triggered autoreactivity. Clinical presentation typically involves rapid, diffuse hair thinning over the scalp with preservation of follicular openings, often mistaken for TE or female pattern hair loss. Dermoscopic examination may reveal exclamation point hairs, yellow dots, and short regrowing hairs, while scalp biopsy can confirm peribulbar lymphocytic infiltrates consistent with alopecia areata. In cases temporally linked to vaccination, the immunologic trigger is hypothesized to involve vaccine-induced activation of type I interferon pathways, molecular mimicry, or dysregulation of regulatory T-cell function in genetically predisposed individuals. Treatment approaches mirror those used in conventional alopecia areata and include high-potency topical corticosteroids, intralesional corticosteroid injections, and systemic immunomodulators in severe cases. In the context of vaccine-associated onset, careful counseling is highly recommended to address patient concerns and clarify the rarity of this adverse event. Recognition of AAI in perimenopausal women following mRNA COVID-19 vaccination requires heightened clinical awareness to ensure accurate diagnosis, timely intervention, and avoidance of misclassification as androgenetic alopecia or nonspecific TE. Dermatologists should maintain a high index of suspicion for autoimmune hair loss variants in the post-vaccination setting and apply dermoscopic, histologic, and clinical tools to guide management and patient education.
