Female pattern hair loss is a common condition which is manifested as a diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline in women. The prevalence of this condition, often referred to as female androgenetic alopecia, increases with advancing age, and has been widely thought to be the female counterpart of male balding.
Most women with female pattern hair loss have clinical signs of gradual thinning of scalp hair, often over a period of several years. Although this kind of hair loss can start at any time between early teens and late middle age, studies by Venning and Dawber reported that 13% of premenopausal women had fronto-temporal recession increasing to 37% in postmenopausal women.
The patterns of hair loss in women are not as easily recognizable as those in men. The androgen dependence and the hereditary nature of this process are also not as obvious in affected women as in affected men. There is frequently a history of excessive hair shedding, but unlike telogen effluvium, hair thinning is usually noticed from the very beginning. Clinical examination reveals a widening of the central parting with a diffuse reduction in hair density affecting mainly the frontal scalp and crown. The pattern of hair loss is varied and some women show hair loss that affects only a small area of the frontal scalp, whereas in others the entire scalp may be involved, including the parietal and occipital regions.
There is also variability in the rapidity of progression and final degree of hair loss. The vertex balding seen in men is rare in women. The frontal hairline is typically retained in women, though women minor degree of post-pubertal recession at the temples is not uncommon. Observations of women who have more pronounced temporal recession show that this recession usually manifests more as thinning rather than the complete loss of temporal hair seen in men.
Knowledge of the dynamics of hair follicle cycling in normal as well as balding scalp is the key to understanding the clinical presentation of androgenetic alopecia. In normal scalp, the average duration of the anagen or growth phase of hair several years; and that of the telogen (resting) phase is 3 months. However, in pattern hair loss, the growth cycle is altered, resulting in a progressive reduction in the duration of the anagen phase. As a consequence, there is production of short, thin, hypo-pigmented, insignificant wisps of hair, and the condition is perceived as balding.
Classification of female pattern hair loss – Ludwig
Although it was a well established fact that women commonly develop an age-dependent form of scantiness of scalp hair, Ludwig has been rightly credited with classifying the clinical presentation of female pattern hair loss. In 1977, he described the distinctive features of female pattern hair loss and classified it into three grades of severity, often referred to as Ludwig I (mild), II (moderate) and III (extensive). In all three Ludwig stages, there is hair loss on the front and top of the scalp with relative retention of the frontal hairline. The back and sides of the scalp may or may not be involved.
Ludwig Classification – 3 Type Female Hair Loss:
- Type I: is described as early thinning that can be easily camouflaged with proper grooming.
- Type II: is characterized by significant widening of the midline part and noticeably decreased volume.
- Type III: manifests as a thin, see-through look on the top of the scalp, often associated with generalized thinning. In this stage the hair becomes very sparse over the top of the scalp but a rim of hair is retained along the frontal margin.
The sparseness of hair in Androgenetic alopecia in both men and women is attributed to decrease in hair density. It has been found that mean hair density on the frontal scalp of women becomes progressively lower with increasing age after the age of about 40 years. Hair diameter is one factor which is considered in clinical assessment, but there may be others such as curl and hair fiber stiffness.
Differences in pattern hair loss in men and women
Women generally exhibit a diffuse thinning (less hair all over), in contrast to men who more frequently have a “patterned” type of hair loss that spares the back and sides. Women often retain their frontal hairline, whereas men characteristically lose a significant amount of hair in the front part of their scalp from the outset. Hair loss in women is most often very gradual, with the rate accelerating during pregnancy and at menopause. It is more often cyclical than in men, and is more easily affected by hormonal changes, medical conditions, and external factors.
Demographic and other data on female androgenetic alopecia
Although low hair density is the major factor in assessing hair loss, other factors relating to hair quality contribute to the subjective assessment of hair status. This theory is purported by the observation that although average hair density is lower in Korean women than in European women, the frequency of clinical hair loss in this racial group is apparently much lower. This discrepancy is presumably due to racial differences in other characteristics of the hair which affect its overall appearance.