Etiology and diagnosis of androgenetic alopecia

Effects of minoxidil 2% vs. cyproterone acetate treatment on female androgenetic alopecia: a controlled, 12-month randomized trial

BACKGROUND

Hormone studies have demonstrated the androgen-dependent character of female androgenetic alopecia, but there have been few controlled studies of therapies for alopecia in women.

OBJECTIVES

To compare topical minoxidil 2% and cyproterone acetate in the treatment of female alopecia.

METHODS

Sixty-six women with female-pattern alopecia were randomly assigned for 12 cycles into two groups, 33 received two local applications (2 mL day-1) of topical minoxidil 2% plus combined oral contraceptive and 33 received cyproterone acetate 52 mg day-1 plus ethinyl oestradiol 35 microg for 20 of every 28 days.

RESULTS

A mean reduction of 2.4 +/- 6.2 per 0.36 cm2 in hairs of diameter > 40 microm was observed in the cyproterone acetate group (P = 0.05) and a mean increase of 6.5 +/- 9 per 0.36 cm2 in the minoxidil group (P < 0.001). Comparison of the total number of hairs at 12 months and the body mass index (BMI) revealed a borderline positive correlation in the cyproterone acetate group (r = 0.39, P = 0.06) and a negative correlation in the minoxidil group (r = -0.42, P < 0.05). No significant difference was observed in the total number of hairs among cyproterone acetate patients according to the presence or absence of other symptoms of hyperandrogenism, whereas in the minoxidil group, the total number of new hairs was higher in patients with isolated alopecia (Delta = 8.1; P < 0.05). Variations in scalp seborrhoea were significant in both groups, but the result was better (for acne and hirsutism as well) in the cyproterone acetate group than in the minoxidil group (P < 0.001).

CONCLUSIONS

Minoxidil treatment was more effective in the absence of other signs of hyperandrogenism, hyperseborrhoea, and menstrual cycle modifications when the BMI was low, and when nothing argued in favour of biochemical hyperandrogenism. Cyproterone acetate treatment was more effective when other signs were present and when the BMI was elevated, factors that favoured a diagnosis of biochemical hyperandrogenism.

Use of topical minoxidil therapy for androgenetic alopecia in women

BACKGROUND

Androgenetic alopecia is the most common cause of hair loss in men and women. Androgenetic alopecia in women begins as a diffuse and progressive thinning of the frontoparietal area of the scalp. In women, hair loss at any age is socially unacceptable and may be the basis of psychiatric illness.

METHODS

A 32-week, double-blind, placebo-controlled trial was conducted in 10 European centers to assess the efficacy and safety of 2% topical minoxidil solution for the treatment of androgenetic alopecia in women. Two hundred ninety-four of the 346 women enrolled (85%) completed the 32-week trial. Photographic and computer imaging techniques were used at each visit to determine objectively the number of nonvellus hairs present in a 1-cm2 area selected as the target evaluation site.

RESULTS

In the 2% minoxidil group, the mean increase in nonvellus hair count was 33 hairs, which was significantly greater than that of 19 hairs in the placebo group (P = 0.0001). The investigators observed that 44% of the patients in the 2% minoxidil group achieved new hair growth compared with 29% in the placebo group. When asked to evaluate their own hair growth, 55% of the women in the 2% minoxidil group compared to 41% of the women in the placebo group believed that they had achieved new hair growth. No clinically significant changes in vital signs were observed during the study and no serious or unexpected medical events were reported.

CONCLUSION

Topical minoxidil solution was significantly more effective than placebo in the treatment of androgenetic alopecia in women.

Sex hormone levels and body hair growth in !Kung San and Kavango men from Namibia

The relation between hair growth and levels of sex hormones in serum and saliva was investigated in 256 !Kung San and Kavango men (ages 18 to 39 years) from Namibia/Southern Africa. Serum concentrations of total testosterone (Tser), 5 alpha-dihydrotestosterone (DHT), and estradiol (E2) as well as the level of bioavailable non-SHBG-bound testosterone in the saliva (Tsal) were determined by radioimmunoassay. The distribution and density of scalp and facial hair as well as the development of terminal hair on the chest, abdomen, pubic area, arms, fingers, and legs were categorized using objective criteria. Covariance analyses revealed marked differences in the distribution of body hair in the San and the Negro sample. This is partly explained by a significant influence of androgen and estrogen levels on the growth of terminal hair. DHT and the ratio DHT/Tser are significantly positively related to midphalangeal hair growth and negatively to pubic hair development. Tsal, the bioavailable fraction of total testosterone, exerts a weak positive influence on the degree of arm and leg hair growth; the most significant positive effect on the growth of abdominal, arm, and leg hair in our samples is caused by E2. The ratio Tser/E2 correlates significantly negatively with the arm and leg hair development and the ratio DHT/E2 with the degree of abdominal, pubic, arm, and leg hair, whereas lower DHT concentrations occur in men with stronger hair development.

Expression of the L-Fucose Moiety on Infrainfundibular Follicular Keratinocytes of Terminal Follicles, Its Decreased Expression on Vellus and Indeterminate Follicles of Androgenetic Alopecia, and Re-Expression in Drug-Induced Hair Regrowth

The distribution of various glycoprotein molecules on the surface of follicular keratinocytes was studied with a panel of lectins with specificity for various sugar moieties on biopsy specimens from both bald/balding scalp and normal occipital scalp, of 23 patients with androgenetic alopecia as well as on biopsies of normal forearm skin of four patients. The most significant differences between bald and normal scalp biopsy were noted with Ulex europaeus agglutinin I (UEA I). We noted an increased (91.8% +/- 3.1; mean +/- SE) expression of UEA I binding sites on the infra-infundibular follicular keratinocytes in anagen terminal scalp hairs, compared to 28.5% +/- 5.2 in the indeterminate (anagen) hairs of balding scalps, and 23.2% +/- 6.3 in the anagen follicles of vellus fore-arm hairs. By contrast, the telogen hairs demonstrated minimal UEA I staining: 4.0% +/- 0.8, mean +/- SE in telogen scalp hairs, 1.8% +/- 0.5 in telogen hairs of balding scalps (0% in completely bald scalps, in which all the hairs were in the telogen phase), and 1.9% +/- 0.2 in telogen forearm hairs. The percentage of UEA I staining correlated with the length of the infra-infundibular follicles in all cases studied. In three cases of hair regrowth after hair growth promotors, the UEA I staining increased to 80.6% +/- 6.1 in anagen hairs and correlated with increased length of infra-infundibular follicles. Our data indicate that there are 1) marked differences between anagen and telogen follicles in UEA I binding to infra-infundibular follicular keratinocytes; 2) the percentage of UEA I staining reflects the size (length) of the infra-infundibular hair follicle; and 3) the anagen follicles of balding scalps (indeterminate hairs) show UEA I staining resembling that exhibited by anagen follicles of vellus hairs.