INTRODUCTION
Female pattern hair loss (FPHL), also known as female androgenic alopecia (AGA), is a progressive form of non-scarring hair loss with characteristic pattern of thinning on the crown of the scalp with sparing of the frontal hairline (Ludwig Scale).1,2 The diagnosis can be made by clinical evaluation of the scalp and thorough medical history evaluation. The cause of alopecia in women is often multifactorial, involving temporal factors such as nutritional deficiencies and hormonal fluctuations (post-partum or sudden weight loss).3,4 During the term of normal hair growth, 85% to 90% of the hair follicles are in growth phase (anagen) which lasts for 2 to 7 years and then decelerates during a 2 to 3 week transition phase (catagen) when the hair follicle matrix cells associated with the dermal papilla (DP) undergo apoptosis (cell death). The remaining 10% to 15% of hair follicles have progressed beyond anagen/catagen into a rest phase (telogen). Telogen lasts several months, and concludes with the shedding of the hair shaft as growth of a new hair is initiated.5
In FPHL, premature onset of catagen causes a progressive shortening of the anagen phase. This shift is reflected by accelerated hair shedding over time, decreased ratio of terminal (long, thick, pigmented) hairs to vellus (short, thin, non-pigmented hairs), and overall reduced hair density.6,7
Although an altered hair follicle cycle is similar for both male and female AGA, and a similar pattern of genetic inheritance and some involvement of sex steroid hormones play key factors in both, the specific cause of FPHL is not considered to be androgen-dependent.8-10
Female pattern hair loss is the most common form of alopecia, and is estimated to affect over 21 million women in the United States.11 Typical onset occurs in the reproductive years of life, with a progressive increase occurring post menopause as estrogen production wanes.12,13 Research indicates that approximately 12% of women develop FPHL by the age of 29 years and 25% by the age of 49 years; and that over 50% have some degree of FPHL by the age of 79 years.14 Although hair loss is primarily a cosmetic concern, hair contributes to outward appearance and impacts self-esteem, self-confidence, and psychosocial functioning. Research indicates that a significantly greater proportion of women than men report emotional distress and invest a greater amount of effort in coping with the effects of AGA. Compared with unaffected women, those seeking treatment for AGA also experience more social anxiety, a more negative body image, and a greater sense of powerlessness than unaffected women.15,16
