Babies are developing ‘werewolf syndrome’ after exposure to this common medication
Key Takeaways
Industry Buzz
Many common medications are a big risk, especially for younger children who are more likely to put anything in their mouth. These exploratory ingestions are the reason why more than two-thirds of poison exposures are for children.” — Ryan Marino, MD
For many of these medications, it is possible one pill can kill.” — Ryan Marino, MD
Last week, Spanish newspaper El País reported that 11 babies in Spain have developed hypertrichosis.[] This condition, also called ‘werewolf syndrome,’ is rare among infants and children.
The cases are linked to exposure to topical hair growth medication, minoxidil, prescribed to their adult caregivers.
Baldness treatment backfires
The Pharmacovigilance Center of Navarre (CFN) in Spain began investigating this link in April 2023 after being informed that a baby boy had developed excessive hair on his thighs, legs, and back over a 2-month period. CFN scientists found the infant’s father had been using a 5% minoxidil lotion on his scalp as a treatment for baldness. When the baby was no longer exposed to minoxidil, his excess hair went away.
The CFN then found additional cases linked to minoxidil.[] In all of these cases, symptoms resolved after the caregiver ceased using minoxidil.
There is some risk, however, that other side effects of minoxidil exposure could develop. Hypertrichosis is the most common side effect of minoxidil exposure, but additional side effects can include pericarditis, electrocardiogram alterations, arrhythmia, and fluid retention.
The incidents prompted the CFN to release an information bulletin about infant health and minoxidil.[] The bulletin proposed that minoxidil might be transmissible from caregivers to children through the skin or mouth. This can occur as a result of skin-to-skin contact or as a result of infants sucking or chewing on a caregiver’s hands or heads after they’ve applied the drug.
Minoxidil sold in Europe will now include warnings on the packaging about the risk of hypertrichosis in infants and will advise users to avoid contact with children in areas where minoxidil has been applied.
The US FDA doesn’t currently warn about the potential transfer of minoxidil between caregivers and children or about the risk of infant hypertrichosis.[] However, minoxidil is not recommended for use during pregnancy or breastfeeding due to transfer risks.
Infant outbreak linked to medication mislabeling
In June 2019, a health alert was issued in Spain after 17 cases of infant hypertrichosis were reported across three regions in the country.[] The outbreak was linked to medication contamination.
Spanish pharmaceutical company Farma-Química Sur reportedly mislabeled bottles of oral minoxidil as over-the-counter pediatric omeprazole.
The exposed children were monitored and were not expected to experience long-term health problems.[] Hair growth receded slowly after ceasing minoxidil, but slight liver damage was observed and expected to resolve.
All affected omeprazole was recalled and a public investigation into Farma-Química Sur followed the incident.[] Several involved families individually sued the company, and in 2022 criminal charges were brought against company officials.[]
When kids are exposed to caregiver medications
Pediatric exposure to adult medication is a known health risk. Adult medication prescriptions are linked to increased exposure and poisoning among children of all ages.
“Many common medications are a big risk, especially for younger children who are more likely to put anything in their mouth. These exploratory ingestions are the reason why more than two-thirds of poison exposures are for children,” medical toxicologist, emergency physician, and an associate professor at the Case Western Reserve University School of Medicine, Ryan Marino, MD, explains.
The highest risk has been observed among children ages 0–5 years old.[] Between 2000 and 2009, the majority of emergency department visits for pediatric exposure to adult medication were linked to hypoglycemics, while the majority of serious injuries and hospitalizations were linked to opioids. A range of other commonly prescribed adult medications can also be dangerous for young children.
“Certain medicines, like ones used for high blood pressure, diabetes, and depression, can actually be deadly to small children,” Dr. Marino tells MDLinx. “For example, a pill that lowers an adult’s blood pressure could lower a child’s blood pressure to dangerous, and even lethal, levels. For many of these medications, it is possible one pill can kill.”
What this means for you
Adult medications can present significant dangers for children. The potential risk of exposure to children can be a key piece of medication safety, especially for topical medications. The recent outbreak of 'werewolf syndrome' among infants in Spain serves as a reminder about the importance of keeping caregiver medication away from children.