A recent report from the Navarra Pharmacovigilance Center in Spain has revealed a shocking trend among infants. Eleven cases of hypertrichosis, also known as “werewolf syndrome,” have been detected in babies across Spain since last year, the New York Post reported. The investigation found that caregivers of the infants had used a popular over-the-counter hair-loss treatment containing 5% topical minoxidil. It is believed that the minoxidil was transferred to the babies through skin contact or accidental ingestion. Minoxidil is a medication approved by the U.S. Food and Drug Administration (FDA) that can be sold without a prescription to adults experiencing age-related hair loss.
Notably, Hypertrichosis, commonly referred to as “Werewolf Syndrome,” is a rare condition characterized by excessive hair growth in unusual areas of the body. This condition causes fine hair, measuring up to 5cm in length, to grow on the face, arms, and other parts of the body. Currently, there is no cure for hypertrichosis. Individuals affected by this condition must rely on regular hair removal methods, such as shaving and waxing, to manage their symptoms.
A notable case in 2023 brought attention to “werewolf syndrome” after a breastfeeding infant developed excessive hair growth across their body over two months. An investigation by health officials revealed that the father was using a topical 5% minoxidil solution to treat androgenic alopecia.
Upon discontinuing the minoxidil treatment, the child’s symptoms completely reversed. Similarly, in all reported cases in Spain, the babies’ excessive hair growth subsided once their caregivers stopped using minoxidil solutions.
In a separate case, a two-year-old girl in Malaysia was diagnosed with a rare congenital form of hypertrichosis. The girl’s condition was distinct from the cases linked to environmental exposure to minoxidil.
Health experts have cautioned that minoxidil can be hazardous to infants’ health and may lead to the development of hypertrichosis. The European Pharmacovigilance Risk Assessment Committee has also highlighted the risks associated with minoxidil exposure in infants.
