Quincke's edema and hypersensitivity pneumonitis induced by lenalidomide for multiple myeloma

A 64-year-old man with recurrent multiple myeloma (BJP-κ type) was treated with 15 mg of lenalidomide (LEN) and dexamethasone. He developed Quincke's edema on his eyelid on day 4. Since the edema improved after withdrawal of LEN, the drug was subsequently re-administered at a decreased dose. However, the edema developed again on day 4. After withdrawal of LEN, the drug was administered again with gradually dose escalation, while confirming the absence of eyelid edema. Although edema did not develop, eosinophils and basophils were increased, and the CRP level was elevated. During the third course of LEN administration, his chest CT showed bilateral ground-glass opacity, and LEN-induced hypersensitivity pneumonitis was diagnosed. The pneumonitis resolved after LEN withdrawal and prednisolone administration. These observations suggested that Quincke's edema, eosinophilia and basophilia, CRP elevation, and hypersensitivity pneumonitis might occur due to the immunological effects of LEN, which is classified as an immunomodulatory drug.