Change in hair texture with the use of pomalidomide for multiple myeloma: From straight to curly phenotype.

Introduction: Pomalidomide is used for treating multiple myeloma in patients who have relapsed after prior treatment with lenalidomide and a proteasome inhibitor. Common side effects include mild cytopenias, and deep vein thrombosis. While papulo-erythematous rash has been described, hair effects are rare with this class of agents.

Case report: We describe a 56-year-old man who was diagnosed with multiple myeloma type IgD lambda six years prior. He responded very well to initial treatment with bortezomib-lenalidomide-dexamethasone. After two years, he had a recurrence that was treated with daratumumab-pomalidomide-dexamethasone, and he entered a stringent complete response (CR) within six months. Daratumumab was discontinued after twelve months, and he subsequently remained on maintenance therapy with pomalidomide. Three months into the maintenance regimen, he noticed a change in hair texture to curly, which continued to progress. Causality assessment linked this change to pomalidomide use via the Naranjo nomogram questionnaire, by scoring 5.

Management and outcome: Pomalidomide maintenance therapy was continued without any dose alterations given the excellent clinical outcome. A year later, multiple myeloma remains in stringent complete response. The patient remains with a curly hair phenotype, having fully embraced his new physical appearance.

Discussion/conclusion: We report herein a unique hair texture alteration linked with pomalidomide use, not previously documented in literature. The observed hair texture change, from straight to curly, requires further investigation. Future studies may offer more insights into the mechanisms underlying this rare, yet intriguing side effect.