LAUSR

Pemigatinib is a Fibroblast grow factor receptor (FGFR) inhibitor used since 2020 as a second line in cholangiocarcinomas and advanced urothelial carcinomas. Dermatological adverse effects, like nail toxicity, have been reported in the phase 2 study, but to our knowledge, there are very few publications about it especially in routine clinical practice cases. A fifty-two-year-old man with unresectable stage IV intrahepatic cholangiocarcinoma included in a clinical trial with pemigatinib was referred due to nail changes that appeared two months after starting therapy. On examination, he presented distal onycholysis of all fingernails (Figure 1) that affected his quality of life. Mild perionixis was observed. No other skin lesions were observed during months of follow-up. The fungal culture of nail sample was negative. The patient was not taking another drug and has no personal or family history of cutaneous diseases affecting nails like psoriasis. No previous similar episodes were recorded. Pemigatinib is a type 2 Fibrobast grow factor receptor inhibitor that was approved in 2020. Its skin toxicity is related to the involvement of FGFR in biological functions such as cell proliferation and differentiation. Dermatological adverse events have been reported in phase II studies including alopecia, palmar–plantar erythrodysesthesia syndrome, stomatitis and nail changes. Nail adverse events, which typically develop within 1–2 months of treatment initiation are typically of mildto-moderate severity. The most reported events have been as follows: onychomadesis, nail discolouration, onycholysis, nails dystrophy, paronychia and onychoclasis. Although less than 5% of cases require a reduction or suspension of treatment, this adverse effect may affect patient’s life quality and may lead to complications such as skin infections. Our patient did not comply with a nail biopsy. Interruption of pemigatinib was not possible due to his oncological process. Nonetheless, the absence of medical history and of skin lesions suggestive of other associated pathologies, such as psoriasis, strongly suggest a causal association two months after the initiation of pemigatinib. Carolina Labrandero Hoyos | Rodrigo Pe~ nuelas Leal | Javier Lorca Spr€ ohnle | Andr es Casanova Esquembre | Felipe Partarrieu Mej ıas | Victor Alegre de Miquel Dermatology Department, Consorcio Hospital General Universitario de Valencia, Valencia, Spain