Concern as babies develop bizarre ‘werewolf syndrome’ after parents use popular hair loss remedy

A popular hair-loss drug may be causing babies to suffer ‘warewolf syndrome’ leaving them blanketed in hair, Spanish health chiefs have warned.

Almost a dozen cases have now been reported in Europe since 2023.

Officials believe the newborns developed the condition after their parents used over-the-counter remedy minoxidil, which is commonly applied to the scalp to encourage hair growth.

‘Werewolf syndrome’ causes abnormal amounts of fine hairs measuring up to 5cm long to grow on a person’s face, arms and other parts of their body.

Known medically as hypertrichosis, it has no cure meaning people must manage symptoms by shaving, waxing or cutting the hair.

According to Pharmacovigilance Centre of Navarra — a province in northern Spain — concerns were first raised about the bizarre phenomenon in April 2023 after a baby boy developed hair on his back, legs and thighs over two months.

Health experts discovered his father, who had been off work for a month looking after him, had been using a five percent minoxidil lotion on his scalp to treat baldness.

However, when the baby was no longer exposed to this drug, his symptoms regressed.

‘Werewolf syndrome’ causes abnormal amounts of fine hairs up to 5cm long to grow on a person’s face, arms and other parts of their body. Stock image

Minoxidil, marketed under the brand name Regaine in the UK, comes in foam or liquid form in a strength of two or five per cent

Minoxidil, marketed under the brand name Regaine in the UK, comes in foam or liquid form in a strength of two or five per cent.

It’s available on Amazon and in most pharmacies with no prescription needed.

The drug works by helping the blood flow to hair follicles — the part of the skin which grows a hair by packing old cells together.

Following the case, the Pharmacovigilance Centre of Navarra then assessed the Spanish Pharmacovigilance System and the European Medicines Agency’s EudraVigilance databases.

WHAT IS HYPERTRICHOSIS?

Hypertrichosis is the term used for the growth of hair on any part of the body in excess of the amount usually present in persons of the same age, race, and sex.

It does not include excessive hair caused by abnormally high levels of male hormones.

Excessive hair may cause embarrassment which leads to it becoming an emotional burden.

Treatment options are limited, and the results of therapy not always satisfactory.

No single method of hair removal is appropriate for all body locations or patients, and the one adopted will depend on the character, area, and amount of hair growth, as well as on the age of the patient, and their personal preference.

The currently available treatment methods include cosmetic procedures; bleaching, trimming, shaving, plucking, waxing, chemical depilatories, and electrosurgical epilation; and hair removal using light sources and lasers.

Laser-assisted hair removal is the most efficient method of long-term hair removal currently available.

Source: American Journal of Clinical Dermatology

According to Spanish newspaper El Economista, they discovered 10 other recent cases of ‘werewolf syndrome’ in babies linked to minoxidil in Europe.

In every case, symptoms reduced after the parent stopped taking minoxidil.

However, the health body warned that very young babies exposed to the drug may be at risk of damage to their heart and kidneys.

Previous research has also shown that even a teaspoon placed on the scalp of an adult twice daily can cause rapid heartbeat and issues with salt and water retention.

In its report, the Pharmacovigilance Centre of Navarra said minoxidil was likely to have transferred from parents to their babies either via the skin or mouth.

As the medicine is applied directly to the skin, a baby might be exposed by trying to suck or chew their parent’s heads or hands after they had applied the drug.

In light of these incidents, minoxidil sold in Europe will now have to include warnings on its packaging about the risk of hypertrichosis in infants, advising users to avoid contact with young children in the areas the medication has been applied.

In 2019, at least 17 children in Spain, some of them babies, developed ‘werewolf syndrome’ after a hair loss treatment was mistakenly placed in bottles of reflux medication.

The kids began growing hair all over their bodies after being given what was thought to be omeprazole, a medication that helps with acid reflux.

But following an investigation, authorities discovered that the treatment actually contained minoxidil.

At the time, health minister Maria Luisa Carcedo said they found the faulty batches came from a laboratory that had ‘put this drug (minoxidil) in a container that was marked as omeprazole ‘ and distributed it to pharmacies as such.’

It comes as minoxidil took the internet by storm earlier this year after social media users discovered it could act ‘like fertiliser for your eyebrows’.

When used two or three times a week, the drug ‘significantly’ improves eyebrow hair growth, advocates say.

Other medics, however, cautioned the treatment is not licenced for this use and may even trigger side effects including hair loss ironically, if used incorrectly.

The NHS also advises minoxidil is only designed to treat male and female hair loss that runs in the family.

It is not intended to treat hair loss caused by other factors including stress, illness or even iron deficiency.