Oral Minoxidil in Children 10 Years of Age and Under: Loose Anagen Hair Syndrome as Model

How Safe is Oral Minoxidil in Children?

Oral minoxidil is increasingly used in adults for a range of different hair loss conditions including androgenetic alopecia, chronic telogen effluvium, alopecia areata, traction alopecia, post chemotherapy induced alopecia and scarring alopecia.

Oral minoxidil has not been well studied in children. I read with great interest a report by Jergen and colleagues regarding the use of oral minoxidil in young children with a diagnosis of loose anagen syndrome aged 2-10 .

Jergen et al, 2021

Jergen and colleagues described their experience using oral minoxidil in 8 children with loose anagen hair syndrome. Children had either failed topical minoxidil or directly started oral minoxidil for other reasons.

The dose of oral minoxidil started in these patients was based on body weight and less than 0.02 mg per kg. Patients were first screened for any cardiac concerns and then had their heart rate and blood pressure monitored every 1-3 months.

Eight girls were included in the study. Median age was 7 with a range 2-10 years. Of the 8 patients in the study, one was age 2, one was age 3 and one was age 4. The remainder were 6, 7, 7, 7, and 10 years. The mean dose of oral minoxidil was 0.01 mg per kg. Patients used oral minoxidil from 7-26 months. 7 patients had an improvement in density. All patients achieved a reduction in shedding.

Side Effects of Oral Minoxidil in Children Under 10

1 of the 8 patients developed a side effect of mild hypertrichosis of the legs but continued treatment. None of the 8 patients had heart or breathing issues and none of the 8 patients had blood pressure or heart rate alterations or weight gain.

One patient developed mild hypertrichosis of the legs but continued treatment. None of the patients reported cardiac or respiratory symptoms, had abnormal vital signs or abnormal weight gain. Interestingly, two patients experienced a change in hair colour during treatment (from reddish/dark brown to light brown). Seven to 18 months after initiation, LDOM was discontinued in six patients whose hair was visibly denser and longer. Two patients are receiving ongoing treatment. Our findings suggest that LDOM is a promising treatment for LAHS, particularly in children at the more severe end of the spectrum. Given the natural history of LAHS and the fact that our patients were very young (mean age 5
75 years), it is likely that the improvement in hair length and density seen in our patients after an average of 12
5 months of treatment was attributable to LDOM rather than spontaneous improvement, which is usually seen by adolescence.

Comment

This is a valuable study that highlights the potential benefits of oral minoxidil in young children. Three of the 8 patients in this study were four years of age or younger so this study is valuable from the perspective that it includes young children. The authors point out that the worrisome complications of tachycardia, pedal edema, weight gain and dizziness seen in adults were not seen in children in this study. They noted that hypertrichosis was the most common side effect.

This study points out that 0.005 to 0.01 mg per kg is probably a good dose to start before adjusting the dose. For an 25 kg patient age 7, that works about to be 0.125 mg or 0.25 mg to start.

REFERENCE

Jerjen R et al. Low-dose oral minoxidil improves global hair density and length in children with loose anagen hair syndrome. Br J Dermatol . 2021 May;184(5):977-978.