Adverse skin effects of imatinib, a tyrosine kinase inhibitor.

Imatinib mesylate is a tyrosine kinase inhibitor that targets the BCR-ABL, c-kit, and PDGF (platelet-derived growth factor) receptors. Imatinib is mainly indicated for chronic myeloid leukemia and gastrointestinal stromal tumors but is also prescribed by dermatologists for dermatofibrosarcoma protuberans, systemic sclerosis, and systemic mastocytosis, among other conditions. Most adverse effects are mild or moderate and therapy is generally well tolerated. Adverse skin effects are very common and include nonspecific manifestations such as edema and maculopapular rashes or eruptions of diverse types (lichenoid or psoriasiform lesions, acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and more). Identifying and properly treating these reactions can help optimize adherence to treatment and improve the prognosis of the underlying disease.

Wolf's isotopic response: a series of 9 cases.

INTRODUCTION: The term Wolf's isotopic response refers to the appearance of a new skin disease at the site of an already healed, unrelated disease. In most cases, the initial disease is herpes zoster. Different diseases may subsequently develop on the same site. The most common isotopic responses are granulomatous and lichenoid reactions, infiltrations of hematologic diseases, skin tumors, and infections. The pathogenesis of these skin reactions is unknown. It has been suggested that viral infection may alter local skin immunity; this would favor hyperreactivity, leading to inflammatory processes, or local immunosuppression, leading to tumor infiltrations or infections. MATERIALS AND METHODS: We performed a retrospective study of 9 patients diagnosed with Wolf's isotopic response in the dermatology department of Hospital Donostia in San Sebastian, Spain. Five patients had B-cell chronic lymphocytic leukemia, 2 had a non-Hodgkin lymphoma, and 1 had ovarian carcinoma. RESULTS: The initial disease was herpes zoster in 7 cases, and chickenpox and herpes simplex in the other 2 cases. The second disease was granulomatous dermatitis in 4 cases, lichenoid dermatitis in 2 cases, infiltration by B-cell chronic lymphatic leukemia in 2 cases, and infiltration by systemic non-Hodgkin lymphoma in 1 case. In the last case, the skin lesions were the first sign of the lymphoma. CONCLUSIONS: We highlight the need to biopsy these second lesions in order to rule out tumor infiltrations, which were more frequent than expected in our series.