INCIDENCE OF ALOPECIA-AREATA IN OLMSTED COUNTY, MINNESOTA, 1975 THROUGH 1989

Objective: To assess the incidence and natural history of alopecia are ata (AA) among unselected patients from a community. Design: We conduc ted a retrospective population-based descriptive study of AA among res idents of Olmsted County, Minnesota, for the period from 1975 through 1989. Material and Methods: After identifying 292 Olmsted County resid ents first diagnosed with AA during the 15-year study period, me revie wed their complete (inpatient and outpatient) medical records in the c ommunity and statistically analyzed the effects of gender and age-grou p. Results: The overall incidence of AA was 20.2 per 100,000 person-ye ars and did not change with time. Rates were similar in the two gender s and over all ages, and lifetime risk was estimated at 1.7%. Eighty-s even percent of patients mere examined by a dermatologist who diagnose d AA, and 29% of cases were confirmed by biopsy, Most patients had mil d or moderate disease, but alopecia totalis or universalis developed a t some point during the clinical course in 21 patients. Conclusion: Th is study of the incidence anti natural history of AA in a community sh ows that this disorder is fairly common and can be seen at all ages, A lthough spontaneous resolution is expected in most patients, a small b ut significant proportion of cases (probably approximately 7%) may evo lve into severe and chronic hair loss, which may be psychosocially dev astating for affected persons.