BOCA RATON, FLA. – Androgenetic alopecia is fairly common in the pediatric population, and in adolescent girls it should prompt an evaluation for hyperandrogenism, according to Dr. Seth J. Orlow.
Androgenetic alopecia is a presenting symptom of polycystic ovary syndrome (PCOS) in a considerable number of cases, he said at the meeting. “I think this is a place where we can really make a difference,” said Dr. Orlow, chair of dermatology and professor of pediatric dermatology, cell biology, and pediatrics at New York University.
One of the most useful lab tests in adolescent girls presenting with early androgenetic alopecia is free and total testosterone, which at elevated levels can serve as a marker for PCOS.
“In a girl who presents with early-onset androgenetic alopecia, think about early presentation of PCOS. It's definitely worth it to test them,” he said.
A chart review of 438 consecutive pediatric patients with alopecia seen by Dr. Orlow and his colleagues over a 12-year period underscored the importance of looking for this diagnosis, and illustrated other characteristics of androgenetic alopecia in both girls and boys. The study showed that androgenetic alopecia was the second most common type of alopecia (after alopecia areata, which accounted for 55% of cases), involving 13% of the cases overall.
Among the 123 adolescent patients, however, 42% (52 patients: 36 boys and 16 girls) had androgenetic alopecia, for a total of 38 boys and 19 girls with androgenetic alopecia among the 438 studied.
Female Findings
Of the 19 girls, 9 had hyperandrogenism. Three had clinical signs and six had biochemical signs of hyperandrogenism. Of the six with biochemical signs, three had elevated free and total testosterone levels, one had elevated free and total testosterone and elevated dihydroepiandrosterone sulfate, one had an elevated free testosterone level only, and one had an elevated total testosterone level only. Seven of the girls were oligomenorrheic, and two were premenarchal. Clinical signs other than the androgenetic alopecia included hirsutism in four girls, acne in six, and seborrheic dermatitis in two.
Other laboratory findings in the 19 girls with androgenetic alopecia included antithyroid antibodies in 1of 5 tested and low serum iron in 3 of 14 tested. None of the girls tested had abnormal thyroid function, iron deficiency anemia, or low testosterone levels, Dr. Orlow said.
The most common presentations in girls were diffuse scalp thinning and thinning at the crown, each occurring in 8 of the 19 patients. The remaining three girls presented with frontal thinning only.
Male Findings
Findings in the boys presenting with androgenetic alopecia included antithyroid antibodies in 1 of 7 tested, hyperandrogenemia in 2 of 14 tested, and low testosterone levels in 3 of 14 tested. None of the boys had abnormal thyroid function, low serum iron, or iron deficiency anemia.
A disproportionate number of boys (13 of the 38) presented with classic female pattern androgenetic alopecia with diffuse thinning of the crown. The remaining boys presented with bitemporal vertex thinning (18 boys), vertex only thinning (4 boys), or frontal and vertex thinning (3 boys), Dr. Orlow said.
Concomitant findings included acne in 32% of the girls and 50% of the boys, and seborrheic dermatitis in 37% of the girls and 16% of the boys. A family history of androgenetic alopecia was present in both, with 82% of the boys and 87% of the girls having an affected first- or second-degree relative.
Differential Diagnoses
It is important to consider possible differential diagnoses in patients presenting with what appears to be androgenetic alopecia. These include acute telogen effluvium, chronic telogen effluvium (particularly in girls), and diffuse alopecia areata, he said.
If the clinical diagnosis is unclear – in boys with female pattern hair loss, in girls with very young onset, or if the patient or parents have a great deal of anxiety about the diagnosis – a biopsy may be helpful, he said.
Of the 57 patients with androgenetic alopecia included in his chart review, 14 (5 girls and 9 boys) underwent biopsy; all of the biopsies showed typical features of androgenetic alopecia, including increased vellus/telogen hairs and connective tissue streamers/follicular stelae below small vellus follicles.
Eight of the 14 also had varying degrees of peri-infundibular lymphocytic inflammatory infiltrate and fibrosis.
Treatment
Treatment options for patients with androgenetic alopecia include minoxidil, finasteride (in boys), and spironolactone.
Minoxidil was used in 16 of the 19 girls; 4 of 6 with greater than 6 months of follow-up had stabilized at 1 year. One developed increased facial hair on treatment, which resolved with a switch from a 5% to a 2% formulation, Dr. Orlow said. Two patients discontinued treatment because of a lack of efficacy and/or headache and nausea.