Management and successful desensitization in methotrexate-induced anaphylaxis.

Anaphylactic/anaphylactoid reactions to methotrexate are rare. In patients with methotrexate-induced anaphylaxis, discontinuation of treatment may increase the risk of death due to cancer progression. In such patients, desensitization may enable the patient to continue treatment with methotrexate. We report the case of a child with metastatic osteosarcoma, who experienced an anaphylactic/anaphylactoid reaction to methotrexate. Skin tests with methotrexate were not performed because their diagnostic value is controversial. Desensitization with methotrexate was successful and allowed the patient to complete 12 additional courses of chemotherapy. Thus, we confirm that desensitization may be a safe procedure in patients with cancer who experience methotrexate-induced anaphylaxis. (c) 2008 Wiley-Liss, Inc.