Response to minoxidil in severe alopecia areata correlates with T lymphocyte stimulation.

Mitogen-induced T cell blastogenesis was determined in 47 patients with severe alopecia areata, before and after treatment with topical 5% minoxidil, and compared with control values. The group of 36 responders, who demonstrated terminal hair regrowth, showed significantly increased lymphocyte stimulation with concanavalin A and PHA before treatment, which decreased towards control values following hair regrowth. Lymphocytes from non-responders showed no significant differences from controls either before or after treatment. The results suggest that enhanced T cell blastogenesis may predict the response of severe alopecia areata to topical 5% minoxidil therapy.

Evaluation of oral minoxidil in the treatment of alopecia areata.

A dose-response effect has previously been demonstrated in topical minoxidil treatment of alopecia areata. Limitations in minoxidil solubility and percutaneous absorption have impaired the development of more effective topical therapy. Oral minoxidil (5 mg every 12 hours), a dose demonstrated to be relatively well tolerated if a 2-g sodium diet is strictly followed, was given to 65 patients with severe, treatment-resistant alopecia areata in an attempt to bypass the limitations of topical treatment and increase efficacy. Although hair regrowth progressed more rapidly and was more extensive with oral than topical 5% minoxidil, cosmetic response was seen only in 18% of the patients. Neither serum nor tissue levels of minoxidil correlated with response. These findings suggest that improved preparations of topical minoxidil, when used as a single therapeutic agent, are unlikely to be cosmetically effective in the majority of patients with severe alopecia areata.

Evaluation of anthralin in the treatment of alopecia areata.

Anthralin cream 0.5% to 1.0% was used to treat 68 patients with severe alopecia areata. Therapy was relatively well tolerated, although all patients experienced pruritus and local erythema and scaling. Cosmetic response was seen in 17 (25%) of the patients, and was maintained during therapy in 12 (71%) of the 17 cosmetic responders. For the patients treated with 0.5% anthralin, the mean time to response (44 of 66 patients) was 11 weeks; the mean time to cosmetic response (13 of 66 patients) was 23 weeks. Duration of the current episode of hair loss did not correlate with cosmetic response. Compared with other currently available topical treatments, anthralin appears to be a reasonable therapeutic option for severe alopecia areata.

Minoxidil.

Topical minoxidil has shown some promise for the treatment of male-pattern alopecia and alopecia areata. Clinical trials suggest that careful patient selection and appropriate drug formulation are both important factors to maximize efficacy. Side effects attributable to topical minoxidil appear to consist almost entirely of cutaneous reactions in patients who have been studied thus far, i.e., patients without hypertension or cardiovascular disease. The mechanism of minoxidil-induced hair regrowth is not fully understood, but it may involve a synergistic effect of minoxidil on a variety of cell types.

Topical minoxidil therapy for hair regrowth.

The pathogenesis of hair loss, the postulated mechanisms of minoxidil action on hair growth, and clinical trials, adverse reactions, experimental formulations, and percutaneous absorption of topical minoxidil preparations are reviewed. Topical minoxidil seems to normalize hair follicles and increase blood flow to the scalp. In clinical trials of various formulations, results have varied. Improved hair growth occurred after four to six months of therapy; twice-daily application seems to be indicated. The most frequently reported adverse reactions are mild scalp dryness and irritation and, rarely, allergic contact dermatitis. Current recommendations are to reserve topical minoxidil for patients with normal cardiovascular status and to routinely monitor blood pressure, heart rate, and electrocardiographic changes. A new drug application is pending with FDA for use of topical minoxidil in androgenetic alopecia (male-pattern baldness), which is genetically determined and apparently stimulated by androgens. For alopecia areata, which involves hair loss on the body or scalp, usually patchy and of sudden onset, no reliable treatment has been found, although minoxidil may be efficacious in some patients. Minoxidil has generated new interest in hair-loss research. The etiology of hair loss must be better understood before more effective treatment regimens can be designed.

Potential mechanisms of minoxidil-induced hair growth in alopecia areata.

In vivo, topical minoxidil therapy is associated with changes in the follicular epithelium, tissue and blood lymphocyte populations, lymphocyte blastogenic response to mitogens, and perifollicular vasculature. Biopsy specimens taken from areas of terminal hair regrowth show a dose-dependent increase in hair follicle length, a decrease in tissue lymphocyte populations associated with a simultaneous increase in peripheral blood lymphocyte counts, and reopening of previously closed lumina of perifollicular vessels. Responder lymphocytes show pretreatment-increased concanavalin A and phytohemagglutinin-induced blastogenesis, which decrease toward control values after treatment. In vitro, at concentrations approximating the range of tissue levels in patients treated topically with the 5% solution, minoxidil affects both epithelial cells and lymphocytes in tissue culture. Cultured murine epithelial cells show increased cell proliferation and delayed senescence. Cultured human lymphocytes show suppression of mitogen-induced blast transformation. Differential effects on responder, nonresponder, and control lymphocytes are seen. Minoxidil may induce hair regrowth in alopecia areata by a synergistic stimulatory effect on follicular epithelium and a suppressive effect on lymphocyte-mediated immunologic phenomena. A contributing role for its vasodilatory properties must also be considered.

Topical minoxidil solution (1% and 5%) in the treatment of alopecia areata.

Topical minoxidil solution can induce hair regrowth in alopecia areata. A dose-response effect was demonstrated when 48 patients treated with topical 1% minoxidil were compared with 47 patients treated with topical 5% minoxidil. A total of 66 patients were enrolled, 26 of them participating in both study groups. Patients with extensive (75% or greater) scalp hair loss showed a response rate of 38%, defined as terminal hair regrowth, with 1% minoxidil versus an 81% response rate with 5% minoxidil. The current 2% formulation is most likely to elicit cosmetically acceptable regrowth in those with patchy alopecia areata. Occlusion of the treated area appears to be necessary to achieve and maintain maximum results. Nonresponders are most likely to be found among those with the most extensive scalp hair loss. No other clinical features correlate with response to treatment. However, a finding of increased T cell blastogenesis before treatment may predict response. In patients with severe alopecia areata, hair loss generally recurs after treatment is stopped and may recur during treatment. Systemic absorption of topically applied and occluded minoxidil solutions (1% and 5%) was minimal; no clinically significant changes in blood pressure, weight, cardiovascular status, electrocardiogram, electrolytes, complete blood count, or urinalysis were seen. Mild local irritation occurred, and two of the 66 patients developed allergic contact dermatitis to minoxidil, as confirmed by patch tests.

Computer-aided quantification of scalp hair.

In this article we present a statistical model that, when applied in conjunction with existing image analysis technology, allows for a precise quantification of two-component visual fields. Application of this methodology to the problem of quantification of hair density in patients with hair loss disorders yields excellent results. Under photographically controlled conditions this method should yield completely consistent and valid results. The complete absence of subjective bias in the application of this method makes it an extremely attractive alternative to existing procedures. Limitations to the use of this methodology are detailed, and an alternative approach is suggested.

Topical minoxidil dose-response effect in alopecia areata.

Topical 5% minoxidil solution was used to treat 47 patients with severe alopecia areata. Forty patients (85%) had terminal hair regrowth after 48 to 60 weeks of treatment. In the majority of patients, hair regrowth was not cosmetically acceptable. Data were compared with those from a previous study with topical 1% minoxidil solution. Both the percentage of responders and the quality of their hair regrowth were significantly greater with 5% than with 1% topical minoxidil solution. One patient developed an allergic contact dermatitis to minoxidil, but no systemic side effects were detected. The results strongly suggest a dose-response effect for topical minoxidil treatment of alopecia areata and the importance of exploring modifications in dosing and delivery systems to enhance therapeutic efficacy.

Quantification of scalp hair--a computer-aided methodology.

A method for obtaining a quantitative assessment of hair density is described. First, a photographic image of the scalp is digitized onto a high-resolution computer graphics screen. Second, the frequency of each of 256 gray levels (one for each of 500 vertical X 500 horizontal = 250,000 locations on the screen) is obtained and the frequency histogram of gray levels is displayed. Third, a statistical procedure, gaussian mixture analysis, is used to resolve the frequency distribution into two normally distributed component distributions. The first component distribution describes the range of gray levels that are typically associated with hair. The second component distribution describes shades of gray that are typically associated with scalp. The statistical model provides a precise measure of the proportion of the head that exhibits gray levels in each of the two component distributions (hair or scalp). The proportion of the first component distribution is a scale-independent measure of hair density. The difference in this quantity before and after treatment provides an accurate quantitative determination of the change in hair density and hence of the efficacy of treatment.