Department of Bioengineering, Imperial College London, London, UK.
Farjo Hair Institute, Manchester, UK.
Exp Dermatol. 2023 Jul;32(7):1174-1181. doi: 10.1111/exd.14839. Epub 2023 May 26.
Male pattern hair loss (MPHL), also referred to as male androgenetic alopecia (AGA) is the most common type of non-scarring progressive hair loss, with 80% of men suffering from this condition in their lifetime. In MPHL, the hair line recedes to a specific part of the scalp which cannot be accurately predicted. Hair is lost from the front, vertex, and the crown, yet temporal and occipital follicles remain. The visual effect of hair loss is due to hair follicle miniaturisation, where terminal hair follicles become dimensionally smaller. Miniaturisation is also characterised by a shortening of the growth phase of the hair cycle (anagen), and a prolongation of the dormant phase (kenogen). Together, these changes result in the production of thinner and shorter hair fibres, referred to as miniaturised or vellus hairs. It remains unclear why miniaturisation occurs in this specific pattern, with frontal follicles being susceptible while occipital follicles remain in a terminal state. One main factor we believe to be at play, which will be discussed in this viewpoint, is the developmental origin of the skin and hair follicle dermis on different regions of the scalp.
男性型脱发（MPHL），也称为男性雄激素性脱发（AGA），是最常见的非瘢痕性进行性脱发类型，80%的男性在其一生中都会受到这种情况的影响。在 MPHL 中，发际线后退到头皮的特定部位，这无法准确预测。头发从前额、头顶和头顶脱落，但颞部和枕部的毛囊仍然存在。脱发的视觉效果是由于毛囊的小型化，其中终末毛囊在尺寸上变小。小型化的特征还包括头发周期（生长期）的缩短和休眠期（休止期）的延长。这些变化共同导致产生更细和更短的毛发纤维，称为小型化或毫毛。为什么小型化会以这种特定的模式发生，而额部毛囊容易受到影响，而枕部毛囊仍然处于终末状态，目前尚不清楚。我们认为一个主要因素是头皮不同区域皮肤和毛囊真皮的发育起源。
