Hair loss

Abstract

A significant number of men and women experience hair loss. Up to 80% of white men and 40% to 50% of white women are affected at some point in their lives. White men are more likely to experience hair loss than men of other ethnicities. Many factors potentially contribute to hair loss, including hormonal changes, physiologic stress, some chronic illnesses, medications, dietary changes, genetics, and local trauma. People affected by hair loss often experience low self-esteem; personal, social, and work-related challenges; and psychiatric disorders, such as depression and anxiety. The economic impact of hair loss is approximately $3.5 billion each year through purchases of products and procedures. Hair loss is broadly categorized as either nonscarring or scarring alopecia. Forms of nonscarring alopecia include androgenetic alopecia (AGA), also known as hereditary pattern hair loss; alopecia areata (rapid-onset, patchy hair loss); anagen effluvium (rapid shedding of growing hairs); telogen effluvium (rapid shedding of resting hairs); cosmetic hair damage; trichotillomania (a compulsive pulling out of one's hair); and tinea capitis (fungal infection/ringworm of the scalp). AGA is the most common form of hair loss and the only type of alopecia for which FDA-approved nonprescription medications are available. AGA is characterized by progressive, male or female pattern hair loss from the scalp. The goal of self-treatment is to achieve an appearance that the patient considers acceptable with a corresponding decrease in the emotional distress experienced. If a self-treatment approach to hair loss is appropriate, the treatment objectives can be accomplished through cosmetic camouflage and/or the use of topical minoxidil to stimulate hair growth, where applicable. Minoxidil is the only FDA-approved agent for self-treatment of AGA. It is available as 2% and 5% hydroalcoholic solutions and as a 5% solvent-free foam. Minoxidil can be applied by various methods depending on the applicator (i.e., spray or dropper). Administration guidelines for the dosage forms differ, and it is important to instruct patients accordingly. This product is labeled for baldness at the crown of the head in men and for hair thinning in the frontoparietal area in women. The 2% and 5% solutions (1 mL twice daily) and 5% foam (half capful twice daily) are approved for use by men, whereas only the 2% solution (1 mL twice daily) and 5% foam products (half capful once daily) are approved for use by women. When used topically for hair loss, minoxidil appears to increase cutaneous blood flow, promote and maintain vascularization of hair follicles, directly stimulate follicular hypertrophy, and prolong the anagen (active hair follicle) phase. After initiation of minoxidil treatment, an increase in hair loss may occur within the first few weeks of product use. Several months may elapse before hair growth is apparent. In many cases, increased hair density is minimal, and treatment response is difficult to assess. The patient must continue to use the product indefinitely to maintain new growth. The most common adverse effects associated with minoxidil, such as local itching, irritation, and dryness or scaling at the site of application, may be related to the hydroalcoholic/propylene glycol in the product. Use of the 5% minoxidil topical formulation in a propylene glycol–free foam reduces the risk of local adverse effects. Patients with scalp damage from psoriasis, severe sunburn, or abrasions should avoid topical minoxidil. All women, regardless of pregnancy or breastfeeding status, should consult a primary care provider before initiating a minoxidil regimen. Other scalp drugs or hair care products should not be used concomitantly with minoxidil. This medication is not indicated for use on infants, children 18 years or younger, or those with heart disease except under the supervision of a primary care provider. If hair fails to appear within the time specified on the product (generally 4-6 months) despite consistent use of the product, the patient should stop treatment and seek care from their physician.