“Doctor, I’m losing my hair!” This is a common complaint of women visiting the Dermatologist. There are many causes of hair loss, and it is important to perform a thorough history and exam. Distinguishing between scarring and non-scarring hair loss is most important, because in scarring hair loss, the follicles are lost and will not regrow hair. With non-scarring hair loss, the follicles have not been irreversibly damaged, but more likely to be either in a resting phase of growth, or shrinking due to hormonal effects on the hair follicle. These two types of hair loss, or alopecia, are known respectively as Telogen Effluvium, or “outflow of resting hairs”, and Androgenetic Alopecia, or “pattern hair loss”.
Androgenetic Alopecia is a found in about 50 percent of post-menopausal women and unfortunately, approximately 10 percent of pre-menopausal women. It may come as a surprise to some of you reading this, but all women produce testosterone, but in lower levels than men. It is the estrogen produced once puberty starts that protects women from the masculinizing effects of testosterone. The diagnosis of female pattern hair loss can often be made clinically without the need for a biopsy, as the typical pattern is for diffuse thinning on the scalp with preservation of the frontal, or forehead, hairline. Hair shafts are of reduced thickness, known as miniaturization. It is unusual to see the more typically male patterns of vertex baldness and receding forehead hairline in women. Blood tests may be considered to evaluate hormone levels and to exclude other causes of hair loss.
Female pattern hair loss in post-menopausal women is treated with topical and/or oral medications. The first medication used is often topical minoxidil, and both 2 percent and 5 percent formulations are available. It is usually applied once daily when using the 5 percent formula. Unfortunately, many women do not like to apply the medication, as it may affect their hair styling, and possibly their hair coloring. Oral minoxidil, originally used for treatment of high blood pressure, has better efficacy, and is administered in doses lower than those used for management of blood pressure. Hair growth is a side effect of minoxidil therapy for blood pressure. The medication is generally safe and well-tolerated, but excess facial hair may occur and minoxidil should not be used if you have atrial fibrillation, a type of irregular heart beat. Finasteride and dutasteride are also used to treat androgenetic alopecia, as they block a type of testosterone receptor found in the hair follicles in the scalp. Yes, these medications are used in men with enlarged prostates, as there is another type of testosterone receptor found there. Dutasteride is about 3 times more potent than finasteride. The main side effects are decreased sex drive and feminizing effects on a male fetus, and the latter is the reason why these medications should not be prescribed to women of child-bearing age. Other medications have been used, including cyproterone acetate and spironolactone, but larger studies need to be done.