Background:

Mycosis fungoides is a cutaneous T-cell lymphoma. The patch stage is limited to the skin and may spontaneously involute or progress, spreading to peripheral blood, lymph nodes and viscera.

Case report:

64 year-old female with a 6-year history of dermatosis with scaly, poorly delimited and pruritic plaques on the chest and extremities. She had received oral steroids and antihistamines, with transient partial remissions been experienced. Skin biopsy revealed Pautrier’s microabscesses, which are pathognomonic of mycosis fungoides. Positron-emission tomography and peripheral blood smear ruled out dissemination and confirmed patch-stage mycosis fungoides. She received nitrogen mustard topical derivatives, psoralen plus UVA therapy, steroids and tacrolimus. She achieved complete remission at 6 months. Two years later, she was treated with dialyzable leukocyte extract, which reactivated the patch lesions with severe itching; the extract was discontinued. The lesions resolved two weeks after topical clobetasol was applied.

Conclusions:

Th2 predominates in mycosis fungoides. Given that dialyzable leukocyte extract reinforces the Th1 profile, it was unlikely for it to reactivate the disease, but the diversity of lymphocyte immunophenotypes in mycosis fungoides and the complex activation networks caused a paradoxical reactivation.