Department of Dermatology, St Vincent's Hospital, PO Box 2900 Fitzroy, Melbourne 3065, Australia.
Br J Dermatol. 2011 Dec;165 Suppl 3:12-8. doi: 10.1111/j.1365-2133.2011.10630.x.
Androgenetic alopecia affects both men and women. In men it produces male pattern hair loss with bitemporal recession and vertex baldness. In women it produces female pattern hair loss (FPHL) with diffuse alopecia over the mid-frontal scalp. FPHL occurs as a result of nonuniform hair follicle miniaturization within follicular units. Diffuse alopecia is produced by a reduction in the number of terminal fibres per follicular unit. Baldness occurs only when all hairs within the follicular units are miniaturized and is a relatively late event in women. The concepts of follicular units and primary and secondary hair follicles within follicular units are well established in comparative mammalian studies, particularly in sheep. However, discovery of these structures in the human scalp hair and investigation of the changes in follicular unit anatomy during the development of androgenetic alopecia have provided a clearer understanding of the early stages of androgenetic alopecia and how the male and female patterns of hair loss are related. FPHL is the most common cause of alopecia in women and approximately one-third of adult caucasian women experience hair loss. The impact of FPHL is predominantly psychological. While men anticipate age-related hair loss, hair loss in women is usually unexpected and unwelcome at any age. Treatment options to arrest hair loss progression and stimulate partial hair regrowth for FPHL include the androgen receptor antagonists spironolactone and cyproterone acetate, the 5α-reductase inhibitor finasteride and the androgen-independent hair growth stimulator minoxidil. These treatments appear to work best when initiated early. Hair transplantation should be considered in advanced FPHL that is resistant to medical treatments. Hair transplantation requires well-preserved hair growth over the occipital donor area. The psychological impact of FPHL may also be reduced by cosmetic products that improve the appearance of the hair. These agents work to minimize hair fibre breakage, improve hair volume or conceal visible bald scalp.
男性型脱发和女性型脱发都会影响到男女两性。男性型脱发会导致鬓角和头顶脱发,形成男性模式脱发;女性型脱发则会导致整个额部和顶部头发稀疏,形成女性模式脱发。女性型脱发是由于毛囊单位内的毛囊不均匀缩小引起的。弥漫性脱发是由于每个毛囊单位内的终毛纤维数量减少引起的。只有当毛囊单位内的所有毛发都缩小后才会出现秃发,而这在女性中是一个相对较晚的事件。毛囊单位和毛囊单位内的初级和次级毛囊的概念在比较哺乳动物研究中已经得到很好的证实,特别是在绵羊中。然而,在人类头皮毛发中发现这些结构,并研究雄激素性脱发发展过程中毛囊单位解剖结构的变化,为我们提供了对雄激素性脱发早期阶段以及男性和女性脱发模式之间关系的更清晰的认识。女性型脱发是女性脱发的最常见原因,大约三分之一的成年白种女性会出现脱发。女性型脱发的影响主要是心理上的。虽然男性会预期与年龄相关的脱发,但女性的脱发通常是出乎意料的,而且在任何年龄都不受欢迎。为了阻止脱发进展并刺激女性型脱发的部分毛发再生,可选择的治疗方法包括雄激素受体拮抗剂螺内酯和醋酸环丙孕酮、5α-还原酶抑制剂非那雄胺和雄激素非依赖性毛发生长刺激剂米诺地尔。这些治疗方法似乎在早期开始时效果最好。对于对药物治疗有抗性的晚期女性型脱发,应考虑进行毛发移植。毛发移植需要在后枕部供区有良好保存的毛发生长。女性型脱发的心理影响也可以通过改善头发外观的美容产品来减轻。这些药物通过减少毛发纤维断裂、增加毛发体积或隐藏可见的秃发头皮来发挥作用。