Hair-Follicle Patterning

Investigate the Turing instability of the hair-follicle patterning system (12.42). 

Alopecia (1) male pattern baldness (1) Topical minoxidil is worth tryin if the patient Is embarrassed by baldness. Some hair regrowth can be detected in up to S0% but it is rarely cosmetically significant. Most patients who take minoxidil orally for hypertension experience some increased hair growth. It may act by a mitogenic effect on hair follicles. The response occurs in 4-12 months stop treatment if no result in 1 year. 

Minoxidil topical. solution is u.scd to treat alopecia andro-genitica (male pattern baldness). Although (he mechanism is not clearly undcrsItKxl. topical minoxidil is believed to increa.se cutaneous bhxid How. which may stimulate hair growth. The stimulation of hair growth is attributed to va.so-dilation in the vicinity of application of the drug, re.sulting in better nourishment of (he local hair follicle.s. 

Alopecia (male pattern baldness) occurs when hair follicles cannot regenerate because the hair shaft is lost as a result of aging or familial history. Temporary alopecia occurs by the following medications and returns once the patient stops taking the medication ... 

Alopecia is male pattern baldness and occurs when the hair shaft is lost and the hair follicle caimot regenerate. Minoxidil (Rogaine) returns hair growth, but alopecia returns within 3 to 4 months after the patient stops using the dmg. 

There is also a small but significant reduction in the number of hair follicles per square centimeter in male pattern alopecia. A bald area will contain about two-thirds to three-fourths the number of follicles of a normal scalp area (approximately 460 follicles per square centimeter) [13]. 

Tinea capitis Scalp ringworm, a form of ringworm in which hyphae grow in hair follicles, often leaving circular patterns of baldness. 

FIG. 7. Healthily developed cuticle pattern of a human hair follicle. 

Magerl M et al (2001) Patterns of proliferation and apoptosis during miuine hair follicle morphogenesis. J Invest Dermatol 116(6) 947-955... 

In an animal model of AGA, the stumptail macaque monkey, finasteride prevented the decrease in scalp hair that occurs in both sexes of this species with puberty, increased scalp hair weight, and corrected the ratio of anagen to telogen follicles induced by pubertal androgens, such that anagen/telogen follicular balance in individual biopsy sections reverted to a more juvenile (prepubertal) pattern (Rhodes etal., 1994). 

In humans these cycles occur in a relatively random fashion in the follicles at various sites of the body. In certain animals, e.g., the mouse or rabbit, the hair cycle is largely synchronized with regional waves of growth and loss leading to readily discernible areas of hair loss. Other animals are more mosaic (like humans) in their cycles. It is likely that patterns of cycling occur in humans the anterior hair line is one probable candidate. Identifying these minor areas of synchrony in humans has been difficult. 

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