Hair Loss

Hair loss

Definition

Hair loss, or alopecia, is total or partial baldness caused by hormonal changes or physical or mental stress .

Description

Hair loss occurs for many reasons. Some causes, such as hormonal changes, are considered natural, while others signal serious health problems. Some conditions are confined to the scalp, while others reflect disease processes throughout the body.

Causes & symptoms

Androgenetic alopecia occurs in both men and women, and is considered normal in adult males. Also known as male pattern baldness, it is easily recognized by the distribution of hair loss over the top and front of the head (leaving a horseshoe pattern of hair) and by the healthy condition of the scalp. Women with androgenetic alopecia experience hair thinning, particularly over the top of the scalp. The disorder is thought to be caused by a genetic predisposition that triggers the production of certain enzymes that convert testosterone into the hormone dihydrotestosterone (DHT). DHT is known to shrink hair follicles, and can cause partial or complete hair loss.

Alopecia areata and alopecia circumscripta refer to hair loss conditions that can be patchy or extend to complete baldness. The exact cause of alopecia areata is unknown, but it is thought to be triggered by an immune system disorder.

Oftentimes, conditions affecting the skin of the scalp will result in hair loss. The first clue to the specific cause is the pattern of hair loss, whether it be complete baldness (alopecia capitis totalis ), patchy bald spots, thinning, or hair loss confined to certain areas. Also a factor is the condition of the hair and the scalp beneath it. Sometimes only the hair is affected; sometimes the skin is visibly diseased as well.

Fungal infections of the scalp usually cause patchy hair loss. The fungus, similar to the ones that cause athlete's foot and ringworm, often glows under ultraviolet light.

Complete hair loss is a common result of cancer chemotherapy, due to the toxicity of the drugs used. Placing a tourniquet around the skull just above the ears during the intravenous infusion of the drugs may reduce or eliminate hair loss by preventing the drugs from reaching the scalp. However, this technique may not be recommended in the treatment of certain types of cancer. An investigational topical gel that may prevent chemotherapy-related hair loss, known as GW 8510, was in clinical trials as of April 2000.

Systemic diseases often affect hair growth either selectively or by altering the skin of the scalp. One example is thyroid disorders. Hyperthyroidism (too much thyroid hormone) causes hair to become thin and fine. Hypothyroidism (too little thyroid hormone) thickens both hair and skin. Several autoimmune diseases also affect the skin and potentially the hair, notably lupus erythematosus.

Hair loss can also be caused by trichotillomania, a mental disorder or compulsion that causes a person to pull out his/her own hair. In some individuals severe mental or physical stress can cause hair loss, including major surgery or illness, significant life changes (i.e., divorce, death of a loved one), and drastic dietary changes. This type of hair loss is called Telogen effluvium, and is the second most common type of hair loss.

Diagnosis

Dermatologists are skilled in diagnosis by sight alone. For more obscure diseases, they may have to resort to a skin biopsy, removing a tiny bit of skin using a local anesthetic so that it can be examined under a microscope. Systemic diseases will require a complete

evaluation by a physician, including specific tests to identify and characterize the problem.

Treatment

Traditional Chinese medicine (TCM) has a particular understanding of baldness that is different from the allopathic view. TCM recommends foods to eat and others to avoid, herbs to treat hair loss, and special hair massage. One Chinese approach is to first understand where there is weak energy in the body and to strengthen the qi (chi) of those organ systems. Treatment is not a one-shot approach but a well-rounded response.

Vitamins B₆ and biotin are thought to advocate healthy hair growth, as are the minerals zinc, copper , and silica . Fifty milligrams of silica a day is thought to encourage hair growth in young men with alopecia. The herb horsetail (Equisetum arvense ) contains silica, and can be taken as an infusion, or tea. Copper and zinc have been shown to inhibit growth of the enzyme that causes DHT production. Iron supplements may be useful in individuals whose hair loss is caused by anemia or an inadequate intake of dietary iron.

The herbal remedies saw palmetto (Serenoa repens ) and pygeum (Pygeum africanum ) may be prescribed by an herbalist, naturopath, or holistic healthcare professional to stop or slow hair loss. Saw palmetto is thought to stop DHT production, and pygeum influences testosterone production. Both can be taken orally as a dietary supplement. The Chinese herb He Shou Wun (Polygonum multiflorum ) can be taken orally or applied as a topical formula.

For hair loss caused by trichotillomania (hair pulling), behavioral therapy may be a useful treatment program. If the hair pulling or hair loss itself is triggered by stress, there are a number of stress reduction therapies that can promote relaxation , including aromatherapy , muscle relaxation exercises, yoga, guided imagery , and biofeedback .

Allopathic treatment

Successful treatment of underlying causes is most likely to restore hair growth, be it the completion of chemotherapy, effective cure of a scalp fungus, or control of a systemic disease. Drugs such as minoxidil (Rogaine) and finasteride (Propecia, Proscar) promote hair growth in a significant minority of patients, especially those with male pattern baldness and alopecia areata. When used continuously for long periods of time, minoxidil produces satisfactory results in about one-quarter of patients with androgenic alopecia and as many as half the patients with alopecia areata. Both drugs have so far proved to be quite safe when used for this purpose. Side effects of Rogaine include some dryness and irritation of the scalp. Reported side effects of Propecia include infrequent cases of diminished sexual drive and impotence . Propecia is not approved for women because it can cause birth defects.

In 2001, a study was made of immunotherapy with diphencyprone to treat alopecia areata. A lag of three months from start of therapy to development of noticeable hair growth occurred. Researchers noted that the extent of the disease prior to therapy and age at time hair loss began affected treatment success. Patients who were older at onset of baldness had a better success rate than those who were younger. The study concluded that longterm therapy was required for effectiveness.

Over the past few decades there have appeared a multitude of hair replacement methods performed by both physicians and non-physicians. They range from simply weaving someone else's hair in with the remains of an individual's own hair to surgically transplanting thousands of hair follicles one at a time.

KEY TERMS

Autoimmune disease

—Certain diseases caused by the body's development of an immune reaction to its own tissues.

Expected results

The prognosis for individuals with hair loss varies with the cause. It is generally much easier to lose hair than to regrow it. Even when it returns, it is often thin and less attractive than the original crop.

Resources

BOOKS

American Society of Health-System Pharmacists Inc. American Hospital Formulary Service Drug Information. Bethesda, MD: American Society of Health-System Pharmacists Inc., 1998.

Bennett, J. Claude, and Fred Plum, eds. Cecil Textbook of Medicine. Philadelphia: W. B. Saunders, 1999.

PERIODICALS

Amichai, B., M. H. Grunwald, and R. Sobel. "5 Alpha-reductase Inhibitors—A New Hope in Dermatology?" International Journal of Dermatology (March 1997): 182–4.

Lewis, Eric J., et al. "Some Common—and Uncommon—Causes of Hair Loss." Patient Care (December 15, 1997): 50.

Watson, Fiona. "Dermatologists Must Sift Through Alternative Tx." Dermatology Times (November 1997): 5.

Wiseman, Marni C. "Protective Model for Immunotherapy of Alopecia Areata with Diphencyprone." JAMA, The Journal of the American Medical Association (November 21, 2001): 2384.

Paula Ford-Martin

Teresa G. Odle