Flagellate dermatitis as a bleomycin-specific adverse effect of cytostatic therapy: a clinical-histopathologic correlation.

In oncology, bleomycin is a frequently used drug for the treatment of several malignancies. In particular, it is part of chemotherapy protocols in testicular cancer. We report on two patients with testicular cancer who received bleomycin-including chemotherapy and developed flagellate dermatitis. This is a typical adverse effect of bleomycin therapy; however, its pathophysiology has not yet been clarified. We discuss possible pathophysiologic mechanisms for this reaction. In general, it has been postulated that histopathologic findings in flagellate dermatitis share similarities with those observed in fixed drug eruptions. In fact, published cases in the literature have shown a broad variety of histologic changes and the histopathologic investigation of our two patients was not indicative of fixed drug eruption-like changes. Histology of one patient showed a superficial and deep, perivascular and periadnexal infiltrate of lymphocytes and eosinophils with a prominent perisudoral distribution, whereas the other patient was remarkable only for the presence of a rather sparse, superficial, perivascular lymphocytic infiltrate with occasional eosinophils and a few melanophages. Epidermal changes, in particular necrotic keratinocytes, were not present in either patient. We provide an overview of all reported histologic changes in bleomycin-induced flagellate dermatitis, including our experience with two patients. Based on these data, we present a summary of the clinical and histologic features.