Successful desensitization in a child with carboplatin allergy: A case report

Hypersensitivity to platinum is described, although its mechanism is unknow n. Carboplatin and cisplatin are cytotoxic agents containing platinum. Carb oplatin is used to treat childhood tumors. Desensitization to carboplatin h as been reported with some protocols requiring more than 3 days duration. W e present a 30-month-old Mexican boy with hypothalamic astrocytoma, ventric uloperitoneal (VP) shunt, and hypersensitivity to carboplatin that develope d after six courses of treatment. His symptoms included wheezing and mild u rticaria, He failed two attempts before successfully completing three desen sitizations with the following regimen: hydroxyzine 2 mg/kg/d and prednisol one 4 mg/kg/d begun at 48 hours prior to the carboplatin infusion, ranitidi ne 2 mg/kg/d at 24 hours, Carboplatin (1 mg/mL) was given at an initial rat e of 1 mg/h with increments every 15 minutes (2, 4, 8, 16, 32, 40 mg/h). He experienced mild wheezing at 40 mg/h and responded well to steroids, diphe nhydramine, and nebulized albuterol. The infusion was resumed at a rate of 32 mg/h to complete 308 mg. The total time of desensitization was 12 hours. Immediate hypersensitivity intradermal testing to carboplatin was positive at 0.01 mg/mL after initial prick testing. This patient responded clinical ly to premedication according to published anaphylaxis on anaphylactoid des ensitization regimens for radiocontrast dyes, which included corticosteroid s, a combination of H1 and H2 antagonists, and ephedrine, but he continued to have dose-dependent reactions. Dose-dependent reactions may reflect both anaphylactoid and IgE-mediated reactivity in our patient. Desensitization to carboplatin requires monitoring in a controlled environment and careful attention at each infusion because tolerance to previous regimens may not p redict response to subsequent infusions.