Résumé
Twenty-four patients with long standing alopecia areata [AA] [13 females and 11 males, whose ages ranged from 8 to 43 years] were studied. The duration of the disease varied from 3 to 16 years. All patients were subjected to detailed clinical and family history, laboratory and immunological studies. Skin biopsies were taken and stained with H/E and immunohistochemically for CD3, CD4 and CD8. Nineteen patients developed AA before puberty and 15 cases had a wide spread alopecia [7 subtotalis, 4 totalis and 4 universalis]. Five patients gave a family history, two of them were nonidentical female twins. The associated clinical features were Down's syndrome [two cases], atopic eczema [three cases, nail pitting [four cases] and only one case with thyroid disease. Five patients had low serum iron, one patient showed positive antithyroid antibodies and two patients with weak positive antinuclear antibodies. Only a female patient with alopecia subtotalis of 10-year duration had low serum immunoglobulin levels, low B-lymphocytes count and high suppressor T-cell number. Histopathologically, there were a reduced number of hair follicles and an increased number of catagen and telogen follicles. Fourteen biopsies showed moderate to dense infiltrate. The infiltrate affected predominantly the anagen follicles, which were reduced in the size. The infiltrate consists mainly of T-cells [CD3]. T-helper [CD4] cells were predominant in nine biopsies