Patch tests in Sézary syndrome and mycosis fungoides.

A retrospective series of 34 patients with the diagnoses of Sézary syndrome, pre-Sézary syndrome, or mycosis fungoides had had patch testing. Of these, 27 had at least 1 positive reaction (11 of 12 with pre-Sézary syndrome, 6 of 10 with Sézary syndrome, and 10 of 12 with mycosis fungoides). The highest average number of positive reactions was observed in patients with pre-Sézary syndrome (4.7 per patient). There was no predominance of positive reactions to any one allergen, but 13 of the 27 patients reacted to a metal allergen. Only 1 of 5 patients who had photopatch testing had a positive result. This retrospective study revealed delayed contact hypersensitivity responses in this group of patients and should serve as a basis for prospective consideration of contact dermatitis factors in patients with mycosis fungoides and Sézary states.