In the Journals

Isolated female-pattern hair loss may not signal hyperandrogenism

Most women who exhibit a frontal-central pattern of hair loss have normal circulating androgen concentrations and an absence of other androgen-related signs or symptoms, although the condition is observed in as many as 30% of women with polycystic ovary syndrome, according to a report from the Androgen Excess and PCOS Society published in The Journal of Clinical Endocrinology & Metabolism.

A committee task force reviewed studies evaluating female-pattern hair loss published through December 2017 and performed a meta-analysis to obtain pooled prevalence estimates on female-pattern hair loss in women with PCOS. The goal, according to researchers, was to provide evidence-based recommendations for the evaluation, diagnosis and treatment of female-pattern hair loss, as well as assess its association with hyperandrogenism.

Clinical presentation

There are several important differences that distinguish female-pattern hair loss from male-pattern hair loss, including patterns and density in the affected areas, according to the researchers.

The researchers cited two typical patterns of hair loss in women: centrifugal expansion mid-scalp, with preservation of the frontal hair line (defined as the Ludwig pattern), or a frontal accentuation or “Christmas tree pattern” (defined as the Olsen pattern). Women with significant androgenization, however, may develop typical male-pattern hair loss (defined as the Hamilton pattern) that includes vertex thinning.

“Women with [female-pattern hair loss] do not experience the degree of baldness that men with [male-pattern hair loss] do, largely because the miniaturization process is not as profound and not all hairs are affected equally in the involved areas,” Enrico Carmina, MD, professor in the department of health sciences and mother and child care at the University of Palermo, Italy, and colleagues wrote. “Many women with [female-pattern hair loss] may also display parietal thinning, but this should not dissuade against making the diagnosis of [female-pattern hair loss].”

The researchers noted that women with androgen excess who develop female-pattern hair loss usually present during young adulthood, whereas the role of hyperandrogenism in postmenopausal women with female-pattern hair loss remains unclear.

In a quality-effects model assessing nine studies that included women with PCOS, the researchers found that the pooled prevalence of female-pattern hair loss in women with PCOS was 28% (95% CI, 22-34).

Pathophysiology of hair loss

Polygenic susceptibility and increased androgen action in the scalp seem to be the main drivers of scalp hair loss in both men and women, according to the report, which also cited a possible role of low-grade inflammation in the scalp as an additional driver of hair loss. Genome-wide association studies, however, suggest that the genetic components of male-pattern and female-pattern hair loss may be different.

In men, studies suggest that elevated expression of androgen receptors and/or exaggerated formation of dihydrotestosterone in the scalp are associated with hair loss; however, in women, the data are less clear, the researchers wrote.

“In fact, many women with [female-pattern hair loss] present normal androgen levels, and it has been shown that [female-pattern hair loss] may present also in subjects with no androgen receptors,” the researchers wrote.

The report noted that further research on the pathogenesis of female-pattern hair loss is “critically needed.”

Differential diagnosis

Common causes of female hair loss must be distinguished from female-pattern hair loss, the researchers wrote, including chronic telogen effluvium, central centrifugal cicatricial alopecia, frontal fibrosing alopecia and fibrosing alopecia in a pattern distribution. In some cases, a dermatoscopic exam or scalp biopsy may be necessary to differentiate female-pattern hair loss from other causes of hair loss in women, according to the researchers, adding that circulating androgen levels should also be evaluated.

“Androgen measures should include measuring total [testosterone] using a high-quality assay, preferably by mass spectrometry or by an immunoassay including sample extraction and purification, and free [testosterone], either using equilibrium dialysis, competitive binding or ammonium sulfate precipitation, or estimated using [sex hormone-binding globulin],” the researchers wrote.

The report further noted that measurements of iron level, vitamin D, prolactin and thyroid profile may be useful to rule out and treat other conditions that may affect hair regrowth.

Treatment in hyperandrogenic women

For most women exhibiting female-pattern hair loss, topical minoxidil in a 2% or 5% solution is considered the first-line treatment, according to the report. When a patient has severe hair loss or hyperandrogenism, a combination of skin-directed and systemic therapy with an antiandrogen or 5-alpha-reductase inhibitor may enhance results, the researchers wrote. The report cautioned that in women of reproductive age, such treatments should be used concomitant with secure contraception to minimize potential teratogenic risks.

“Although one meta-analysis suggested no significant improvement with either a 5[-alpha]-reductase inhibitor or antiandrogen, multiple small studies, case reports and general prescribing practices suggest otherwise,” the researchers wrote. “More data with outcomes stratified by age, hair loss severity and hyperandrogenism are needed to better understand the efficacy of these agents.”

Agents available to treat female-pattern hair loss include finasteride, dutasteride, the potassium-sparing diuretic spironolactone and the antiandrogen flutamide. Alternative treatments can include low-level laser light therapy, which the report noted may be of modest benefit in female-pattern hair loss, and hair transplantation used in conjunction with continued medical therapy. – by Regina Schaffer

Disclosures: The authors report no relevant financial disclosures.

Most women who exhibit a frontal-central pattern of hair loss have normal circulating androgen concentrations and an absence of other androgen-related signs or symptoms, although the condition is observed in as many as 30% of women with polycystic ovary syndrome, according to a report from the Androgen Excess and PCOS Society published in The Journal of Clinical Endocrinology & Metabolism.

A committee task force reviewed studies evaluating female-pattern hair loss published through December 2017 and performed a meta-analysis to obtain pooled prevalence estimates on female-pattern hair loss in women with PCOS. The goal, according to researchers, was to provide evidence-based recommendations for the evaluation, diagnosis and treatment of female-pattern hair loss, as well as assess its association with hyperandrogenism.

Clinical presentation

There are several important differences that distinguish female-pattern hair loss from male-pattern hair loss, including patterns and density in the affected areas, according to the researchers.

The researchers cited two typical patterns of hair loss in women: centrifugal expansion mid-scalp, with preservation of the frontal hair line (defined as the Ludwig pattern), or a frontal accentuation or “Christmas tree pattern” (defined as the Olsen pattern). Women with significant androgenization, however, may develop typical male-pattern hair loss (defined as the Hamilton pattern) that includes vertex thinning.

“Women with [female-pattern hair loss] do not experience the degree of baldness that men with [male-pattern hair loss] do, largely because the miniaturization process is not as profound and not all hairs are affected equally in the involved areas,” Enrico Carmina, MD, professor in the department of health sciences and mother and child care at the University of Palermo, Italy, and colleagues wrote. “Many women with [female-pattern hair loss] may also display parietal thinning, but this should not dissuade against making the diagnosis of [female-pattern hair loss].”

The researchers noted that women with androgen excess who develop female-pattern hair loss usually present during young adulthood, whereas the role of hyperandrogenism in postmenopausal women with female-pattern hair loss remains unclear.

In a quality-effects model assessing nine studies that included women with PCOS, the researchers found that the pooled prevalence of female-pattern hair loss in women with PCOS was 28% (95% CI, 22-34).

Pathophysiology of hair loss

Polygenic susceptibility and increased androgen action in the scalp seem to be the main drivers of scalp hair loss in both men and women, according to the report, which also cited a possible role of low-grade inflammation in the scalp as an additional driver of hair loss. Genome-wide association studies, however, suggest that the genetic components of male-pattern and female-pattern hair loss may be different.

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In men, studies suggest that elevated expression of androgen receptors and/or exaggerated formation of dihydrotestosterone in the scalp are associated with hair loss; however, in women, the data are less clear, the researchers wrote.

“In fact, many women with [female-pattern hair loss] present normal androgen levels, and it has been shown that [female-pattern hair loss] may present also in subjects with no androgen receptors,” the researchers wrote.

The report noted that further research on the pathogenesis of female-pattern hair loss is “critically needed.”

Differential diagnosis

Common causes of female hair loss must be distinguished from female-pattern hair loss, the researchers wrote, including chronic telogen effluvium, central centrifugal cicatricial alopecia, frontal fibrosing alopecia and fibrosing alopecia in a pattern distribution. In some cases, a dermatoscopic exam or scalp biopsy may be necessary to differentiate female-pattern hair loss from other causes of hair loss in women, according to the researchers, adding that circulating androgen levels should also be evaluated.

“Androgen measures should include measuring total [testosterone] using a high-quality assay, preferably by mass spectrometry or by an immunoassay including sample extraction and purification, and free [testosterone], either using equilibrium dialysis, competitive binding or ammonium sulfate precipitation, or estimated using [sex hormone-binding globulin],” the researchers wrote.

The report further noted that measurements of iron level, vitamin D, prolactin and thyroid profile may be useful to rule out and treat other conditions that may affect hair regrowth.

Treatment in hyperandrogenic women

For most women exhibiting female-pattern hair loss, topical minoxidil in a 2% or 5% solution is considered the first-line treatment, according to the report. When a patient has severe hair loss or hyperandrogenism, a combination of skin-directed and systemic therapy with an antiandrogen or 5-alpha-reductase inhibitor may enhance results, the researchers wrote. The report cautioned that in women of reproductive age, such treatments should be used concomitant with secure contraception to minimize potential teratogenic risks.

“Although one meta-analysis suggested no significant improvement with either a 5[-alpha]-reductase inhibitor or antiandrogen, multiple small studies, case reports and general prescribing practices suggest otherwise,” the researchers wrote. “More data with outcomes stratified by age, hair loss severity and hyperandrogenism are needed to better understand the efficacy of these agents.”

Agents available to treat female-pattern hair loss include finasteride, dutasteride, the potassium-sparing diuretic spironolactone and the antiandrogen flutamide. Alternative treatments can include low-level laser light therapy, which the report noted may be of modest benefit in female-pattern hair loss, and hair transplantation used in conjunction with continued medical therapy. – by Regina Schaffer

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Disclosures: The authors report no relevant financial disclosures.