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.