HISTOPATHOLOGIC FINDINGS OF ALOPECIA AREATA IN VIETNAMESE PATIENTS

Introduction: Alopecia areata is considered as an autoimmune disease affecting hair follicles causing hair loss. Histopathological examination is the most valuable test for the diagnosis of disease. In addition to typical signs of diagnostic value such as lymphocytes densely gathered around the hair bulb into a “swarm of bee” and the ratio of hair follicle types on the specimen, there are a number of studies which have shown that the presence of eosinophils around the hair follicle, the features of follicular necrosis also play a role in the diagnosis and prognosis of alopecia areata.Objectives: To describe histopathological characteristics and to analyze the relationship between those features with some clinical features of alopecia areata in Vietnamese patients.Methods: We recruited 35 patients with alopecia areata diagnosed on clinical findings, dermoscopy and consent for histopathology. In each patient, we biopsied 2 pieces of scalp with a 4mm punch in the marked area. One piece was dissected in the horizontal section and the other piece was sectioned vertically.Results: Average number of hair follicles was 20.1 ± 3.5, average number of hair follicular units was 9.3 ± 1.8. The percentage of specimens in the acute, subacute, and chronic stages was 48.6%, 28.6%, and 22.9%, respectively. There were no specimens in the recovery stage. The mean duration of lesions in the acute stage was 1.8 ± 1.0 months, the subacute and chronic stages were 4.7 ± 1.1 and 23.25 ± 26.3, respectively. In the acute stage slides, 100% of the slides had peribulbar anagen hair lymphocytic infiltration. The number of specimens showing eosinophils accounted for 22.8%. Vacuolization and necrosis accounted for 14.3% of the total specimens.Conclusion: Diagnosis of alopecia areata is made best on histopathologic examination, the histopathological stage discribes more than peribulbar lymphocytic infiltration, such as: percentages of multiple types of hair follicles, variation of histopathologic traits through disease stages.