Pattern hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front hairline, loss of hair on the crown (vertex) of the scalp, or a combination of both. Female-pattern hair loss (FPHL) typically presents as a diffuse thinning of the hair across the entire scalp.
| Pattern hair loss | |
|---|---|
| Other names | Male pattern baldness; female pattern baldness; androgenic alopecia; androgenetic alopecia; alopecia androgenetica |
| Male-pattern hair loss shown on the vertex of the scalp | |
| Specialty | Dermatology, plastic surgery |
Genetic research has identified alleles associated with male pattern hair loss. These alleles appear to be undergoing positive sexual selection in European and East Asian populations, as male pattern baldness may be seen as a masculine attribute associated with seniority and higher social status. The condition is caused by a combination of male sex hormones (balding never occurs in castrated men) and genetic factors.
Some research has found evidence for the role of oxidative stress in hair loss, the microbiome of the scalp, genetics, and circulating androgens; particularly dihydrotestosterone (DHT). Men with early onset androgenic alopecia (before the age of 35) have been deemed the male phenotypic equivalent for polycystic ovary syndrome (PCOS).
The cause in female pattern hair loss remains unclear; androgenetic alopecia for women is associated with an increased risk of polycystic ovary syndrome (PCOS).
Management may include simply accepting the condition or shaving one's head to improve the aesthetic aspect of the condition. Otherwise, common medical treatments include minoxidil, finasteride, dutasteride, or hair transplant surgery. Use of finasteride and dutasteride in women is not well-studied and may result in birth defects if taken during pregnancy.
By the age of 50, pattern hair loss affects about half of males and a quarter of females. It is the most common cause of hair loss. Both males aged 40–91 and younger male patients of early onset AGA (before the age of 35), had a higher likelihood of metabolic syndrome (MetS) and insulin resistance. With younger males, studies found metabolic syndrome to be at approximately a 4× increased frequency which is clinically deemed significant. Abdominal obesity, hypertension and lowered high density lipoprotein were also significantly higher for younger groups.