There was a case reported to a Spanish pharmacovigilance center in April 2023 where an infant developed hair growth to the back, legs and thighs over a period of 2 months. When investigated, it was discovered that the father was using Minoxidil 5% on his scalp for hair growth. After he stopped using the treatment, the infant’s symptoms stopped as well.
There have been 11 similar cases reported to the pharmacoviligance authorities in Europe.
Mechanism of Transmission Unclear
The exact mechanism by which caregivers transfer minoxidil to infants is not fully understood. In the newly identified cases, scientists suspect the drug was transmitted through direct or indirect contact. Direct contact could also take place when holding the infant’s head touching the caregiver’s scalp (forehead, temple region). Accidental ingestion is also a possibility if the infant’s hands touched treated areas on the caregiver’s scalp skin and were then brought to the mouth.
Infants’ skin is more permeable due to the thinner stratum corneum and a higher surface area/body weight ratio, making them more susceptible to absorbing topically applied medications.
Precautions
Recommended precautions for patients include thoroughly washing hands after applying the product and covering treated areas to prevent direct contact with infants’ skin.