Some authors have reported that severe destruction of follicular structures and even scarring patterns occur in those patients with alopecia areata (AA) who fail to respond to topical immunotherapy with contact sensitizers, such as diphencyprone (DCP). Other studies, however, gave contradictory results. Therefore, we re-examined histopathological changes in scalp samples obtained from 85 patients with severe alopecia areata before initiation of DCP treatment (40 responders and 45 non-responders in terms of hair regrowth after DCP treatment). The following parameters were evaluated: i) perifollicular lymphocytic infiltration; ii) perifollicular fibrosis, and iii) miniaturized hair follicles. No difference between responders and non-responders could be observed in the degree of miniaturization of hair follicles and proliferation of perifollicular fibrous tissue. In neither group was there any evidence of scarring or severe follicular destruction. 18 non-responders but only 6 responders showed a very dense perifollicular lymphocytic infiltration. In contrast, a particularly scarce infiltrate was seen in 9 non-responders and in 19 responders. We conclude that non-responders to topical sensitizers tend to have rather pronounced inflammatory reactions with dense perifollicular lymphocytic infiltrates.