Topical immunotherapy changes the composition of the peribulbar infiltrate in alopecia areata

It has previously been shown that, in patients with untreated progressive alopecia areata (AA), the peribulbar T4/T8 ratio is about 4:1. In the present study, the immunohistochemical findings obtained in untreated AA patients were compared to those obtained in patients who had received topical immunotherapy with diphencyprone. The untreated group consisted of 5 patients with progressive AA and 5 patients with inactive AA. The treated group consisted of 5 patients with a good response to diphencyprone and 5 patients with little or no hair regrowth after treatment. In untreated patients with progressive AA, the mean peribulbar T4/T8 ratio was 4:1, whereas in untreated patients with stable AA, the ratio was 2:1. In the treated patients with a good response to diphencyprone, the mean T4/T8 ratio was 1:1, while in the patients with poor or no response to treatment, the ratio was 0.7. In conclusion, topical immunotherapy considerably alters the peribulbar T4/T8 ratio in AA. The results are consistent with, but do not prove, the concept of topical immunomodulation.