Prevalence of thyroid diseases in patients with alopecia areata.

BACKGROUND: The prevalence of thyroid disease in patients with alopecia areata previously reported varied from 0 to 28%. These thyroid diseases, include Hashimoto's thyroiditis, Graves' disease, simple goiter, and others.

METHODS: The prevalence of thyroid diseases was determined in 152 consecutive patients with alopecia areata who presented to the dermatology clinic. A complete history was taken and a physical examination was performed. Thyroxine, triiodothyronine, thyroid-stimulating hormone, and microsomal antibody levels were measured in every patient. The control group consisted of 152 age- and sex-matched volunteers who had skin diseases other than alopecia areata or autoimmune disorders.

RESULTS: Among 152 patients, age 10-59 years, four cases (2.6%) had a small simple goiter. Microsomal antibodies were detected in seven other patients (4.6%) with titers ranging from 1:100 to 1:1600. None of these seven patients had signs or symptoms of thyroid disease. Five cases (3.3%) of the control group had positive microsomal antibody tests with titers ranging from 1:100 to 1:400. The prevalence of positive microsomal antibodies in the alopecia areata group was not statistically different from the control group (chi 2 = 0.347, DF = 1, P = 0.5558).

CONCLUSIONS: Among 152 patients with alopecia areata, 4.6% of patients had microsomal antibodies and 2.6% had a small simple goiter. Thus the prevalence of thyroid disease among these patients was 7.2%. The prevalence of positive microsomal antibodies in 4.6% of the patients was not statistically different from that of the control group.