NORMAL CHANGES OF AGING
Age-related structural and functional changes in skin are summarized in TABLE 101-1. Age-related changes in hair and nails are discussed below.
Hair Changes
Hair begins turning gray in about 50% of persons by age 50.
Frontotemporal hair loss (androgenic alopecia) in men begins in the second or third decade; by the seventh decade, 80% of men are substantially bald. In women, the same pattern of hair loss may occur after menopause, although it is rarely pronounced.
Diffuse alopecia normally occurs in both sexes with advancing age; however, it can also result from iron deficiency or hypothyroidism, so these conditions should be excluded when indicated. Certain drugs (especially anabolic steroids and antimetabolites), chronic renal failure, hypoproteinemia, and severe inflammatory skin disease such as erythroderma can also cause diffuse alopecia.
Hair loss with scarring is relatively rare and not associated with aging but with disease. It can be caused by deep bacterial or fungal infections; granulomatous disorders such as sarcoidosis, tuberculosis, or syphilis; and inflammatory disorders such as lichen planus and cutaneous lupus erythematosus. Cicatricial pemphigoid is a chronic bullous eruption that affects mucous membranes and sometimes the scalp. Biopsy of the scalp is usually necessary to make these diagnoses.
Hirsutism, excessive or unwanted hair, is also common after the fifth decade, especially in women, presumably as a result of the altered estrogen-androgen balance in hormonally sensitive hair follicles. In women, the most common complaint is the appearance of scattered terminal hairs in the beard area. Men may note increased hairs in the eyebrows, nares, or ears.
Treatment: Topical minoxidil solution can be used to treat physiologic age-associated hair loss. When applied daily to bald areas, it stimulates regrowth in 25% to 30% of patients, particularly in those who begin treatment early. However, cosmetically significant regrowth occurs in < 10%, and even these patients usually begin to lose hair again within 1 yr. Hair transplantation can be performed by several techniques, including one in which punch grafts from the occipital areas are transplanted to the bald temporal areas. The cosmetic results of this procedure can be enhanced by scalp reduction. Hair loss from endocrine, metabolic, inflammatory, or nutritional disorders can be fully reversed by correcting the underlying disorder.
Unwanted hairs can be repeatedly plucked or cut. Alternatively, the follicle can be permanently destroyed by electrolysis.
Nail Changes
The thickness, shape, color, and growth rate of the nails change with age, reflecting changes in the supporting nail bed and germative matrix. They become dry and brittle and flat or concave instead of convex, often with longitudinal ridging. The color may vary from yellow to gray. Occasionally, the nails become grossly thickened and distorted, a condition known as onychogryphosis.
Treatment: No effective treatment exists for these nail changes. For the patient’s safety and comfort, a podiatrist should trim thickened toenails with an electric drill and burrs or a carbon dioxide laser. Wearing gloves while doing housework and laundry protects brittle fingernails. Nails should be kept short, and use of nail polish remover, which dehydrates the nail, should be minimized. Evaluation by an experienced examiner can determine treatable conditions, such as fungal infections.