Hair Loss
Male pattern hair loss is a member the conditions known as nonscarring alopecias. Another nonscarring alopecia is alopecia areata. Here, Ihair loss is often confined to one or more small oval patches; in others, the scalp is virtually denuded except for a few tufts of hair. Alopecia areata may extend to the entire scalp (alopecia totalis) or to the surface area of the whole body (alopecia universalis). The condition is marked by exacerbations and recoveries. When hair regrows, it may assume a white discoloration.

Some grooming methods may cause a nonscarring alopecia. These include ponytails, braids, tight curls, or cornrows involves pulling hair in unnatural positions. Some hair is gathered tightly and secured. The tension on hair causes many strands to be pulled from the scalp prematurely. This traction alopecia (hair loss) often is associated with patterned hair loss on the temporal regions, periauricular zones, and frontal scalp.

Hair Loss Regrowth
Androgenetic alopecia produces gradual thinning of the hair. Hair loss is pronounced over the crown in both men and women, and, in men, also on the front of the scalp. In men, the onset is usually in the teens, while, in women, many usually notice the problem appearing or markedly worsening at menopause.

The patient may have a family history of androgenetic alopecia. For many years, common wisdom held that people inherited male pattern baldness from their mothers. . However, inheritance is polygenic, so either or both parents can pass the tendency to a child, which explains why brothers may vary widely in their degree of hair loss.⁹ Nevertheless, if a patient (male or female) contemplating self care has no history of hair loss in any family member, the labeling information on self-treatment products suggests a physician visit.

Minoxidil
Topical minoxidil for pattern hair loss is unusual because it is the first FDA-approved medication used for cosmetic purposes. It is the only nonprescription ingredient proven to regrow hair, despite the numerous Web sites promoting unproven products. The mechanism of minoxidil is uncertain. A 2% solution provided regrowth statistics from a major efficacy study demonstrating that men ages 18 to 49 with moderate hair loss have a 26% chance of experiencing moderate to dense hair regrowth in four months and a 33% chance of minimal regrowth.¹⁰ After eight months of use, women ages 18 to 45 with mild to moderate hair loss can expect moderate regrowth in 19% of cases and minimal regrowth in 40% of cases.¹¹ Those whose hair loss is recent and minor have the best chance for decent regrowth.

How is Minoxidil Applied? The patient should apply 1 mL of minoxidil twice daily. Packages contain several applicator options, including a dropper marked with a 1-mL calibration, a spray applicator, and an extended-spray applicator, which is ideal for long hair. Six pumps of the applicators release 1 mL of minoxidil. Because systemic absorption could affect blood pressure, the patient should not inhale the aerosol generated by the spray applicators.

After minoxidil reaches the scalp, it must remain in contact for at least four hours for full absorption. During this time, the patient must not swim, wash hair, allow rain to contact the head, or engage in heavy exercise that would cause sweat to wash away the minoxidil. The solution should be dry before other hair products are applied. Further, minoxidil should be used at least four hours before bedtime, or the solution might be rubbed off onto the pillow during presleep tossing and turning.

Minoxidil Usage Precautions: Several other precautions should be communicated to patients using minoxidil. For instance, patients should not apply more than 1 mL twice daily. Using more than the recommended dosage in a misguided attempt to speed hair growth is not only ineffective but also could lead to adverse reactions such as hypotension. If the patient uses his or her hands to more effectively spread minoxidil onto the scalp, they should be washed thoroughly. Minoxidil should not be used by anyone younger than 18 and is not known to prevent hair loss. Pregnant and breast-feeding women should not use—or even touch—the product, nor should anyone allergic to either minoxidil or the components of the formulation (eg, propylene glycol, alcohol).

Ceasing Minoxidil Use: Should the patient stop using minoxidil, regrown hair will likely be lost within three to four months' time because it is effective only when it is being used. However, an interesting question arises regarding minoxidil's mechanism of action and hair loss after its discontinuation. Suppose identical twins have androgenetic alopecia, each with a 1-inch diameter bald spot on the vertex. One uses topical minoxidil for a 10-year period and has moderate regrowth within the bald spot and no further hair loss.¹² The other twin does not use minoxidil and continues to lose hair during the same 10-year period, with the bald spot enlarging to 2 inches. At the end of the 10-year period, the minoxidil-using twin stops using the product. When his hair falls out, will his bald spot be 1 inch or 2 inches, like his twin's? Unfortunately, minoxidil cannot stop the inexorable march of time and genetics, and the latter will be the case. Thus, long-time users may notice that halting use of minoxidil makes them look worse than before they first used it.

Local Reactions to Minoxidil: Users of minoxidil who experience an allergy to the ingredients should discontinue use. Others notice burning or irritation with use, more often with the 5% than the 2% products.¹³ Local irritation of the scalp may induce pruritus or dryness. Patients may complain that their teenage dandruff seems to have returned in the form of flaking and scaling. Although these are mostly minor problems that do not necessitate discontinuation, patients should see a physician to rule out contact dermatitis. The patient can be urged to purchase a moisturizing shampoo.

Patients Who Should Not Use Minoxidil: Patients must not apply minoxidil to scalp areas that are inflamed, infected, irritated, erythematous, or eczematous. Women should not use the 5% product, since it can cause asymmetrical hypertrichosis, manifesting as de novo growth of dark hair on the face, hands, arms, legs, feet, chest, ear rim, and back.¹⁴ Patients should be advised to discontinue use if they develop chest pain, tachycardia, faintness, dizziness, unexplained sudden weight gain, swelling of the hands or feet, and scaling and erythema of the scalp. Patients who have preexisting cardiac disease should not use minoxidil because of the potential for tachycardia and palpitations.

If a male patient has an inadequate response to minoxidil, the pharmacist can recommend that he see a physician to obtain a prescription for finasteride, an azasteroid that inhibits the enzyme responsible for androgenetic alopecia.^15,16 There are no prescription products for women.