Curling of Hair in Two Female Patients Taking Alitretinoin

Two female patients aged 45 and 51 years experienced curling of hair during treatment with alitretinoin (Toctino^®). For one patient, the indication for use was severe chronic hand eczema, but for the second patient the indication was not reported. After 5 and 9 months, respectively, the patients developed hair texture changes and their straight hair began to curl. The dose of alitretinoin was reduced in both cases, but the patients' hair had not straightened at the time of reporting (9 months and 2 years after onset of the event). Based on the described reports received by the Netherlands Pharmacovigilance Centre Lareb, the case reports in the literature, and the possible mechanisms, we suggest a causal relationship between curling of the hair and the use of alitretinoin. Using the World Health Organization Uppsala Monitoring Centre (WHO-UMC) system for standardized case causality assessment, the association in our cases can be assessed as likely.