TELOGEN EFFLUVIUM AND ANAGEN EFFLUVIUM
Clinical Findings: Telogen effluvium is a form of nonscarring alopecia that can result in dramatic thinning of the scalp hair but rarely causes total hair loss. It has been found to be induced by a number of stressors that cause the anagen hairs to abruptly turn into telogen hairs. This results in an abnormal number of hairs in the telogen phase and an increase in hair shedding. The hair loss can be profound and disconcerting to the patient. Causes include childbirth, major illness or stress, surgery, and medications. The hair loss is less rapid than in anagen effluvium.
Anagen effluvium is a specific form of alopecia that is typically induced by chemotherapeutic agents. Alkylating agents such as busulfan and cisplatin and the antitumor antibiotics (bleomycin and actinomycin D) are frequently responsible. Other agents have been implicated, including the antimetabolites, topoisomerase inhibitors, and vinca alkaloids. The anagen phase hair is particularly sensitive to these chemotherapy agents, which inhibit proliferation of rapidly dividing cells. This form of hair loss is easier to diagnosis, because a history of taking one of the implicated chemotherapeutic agents is critical in making the diagnosis.
Histology: Scalp biopsies are one of the best ways of confirming the diagnosis. The standard procedure is to obtain a 4-mm punch biopsy from the affected region. Instead of the routine vertical sectioning, horizontal sectioning is performed. Punch biopsies have been standarized to 4 mm. The presence of scarring, the form of inflammation, and the ratio of anagen to telogen hairs are evaluated. In telogen effluvium, a normal number of hairs are present without evidence of miniaturization. The ratio of telogen to anagen hairs is increased from the normal 5 to 10 telogen hairs per 100 anagen hairs to more than 20 per 100. Biopsies of anagen effluvium show a normal ratio of anagen to telogen hairs, but the anagen hairs exhibit some evidence of abnormality, either broken shafts or apoptosis of the hair.
Pathogenesis: Telogen effluvium can almost always be traced to a recent illness, surgery, iron deficiency, child bearing, or other major stressor in the patient’s life. Many medications have been reported to induce telogen effluvium, and the clinician should evaluate all medications taken. Dietary habits, especially crash dieting and anorexia nervosa, may lead to telogen effluvium. The hair follicles are not scarred and eventually grow back after the stressors have been resolved. Because the beginning of hair loss may be delayed after the stressful event, by 3 to 4 months on average, the patient may not realize the relationship.
Treatment: The treatment of telogen effluvium consists of determining the etiology and educating the patient. It is important to rule out an underlying disorder (e.g., iron deficiency, hypothyroidism) that may be triggering the hair loss. Once this has been accomplished, patients need to be educated and reassured that telogen effluvium almost always resolves within 6 to 8 months, and they may expect full regrowth. Supple-mental vitamins and topical minoxidil have not been vigorously tested as therapies for telogen effluvium, and their use cannot be scientifically advocated. Referral to a psychological counselor may be appropriate in situations such as eating disorders.
Anagen effluvium is related to the use of chemotherapeutic agents to treat systemic cancer. The therapy should not be stopped because of this side effect. After therapy has been completed, most patients regrow their hair. Patients have reported many changes in the color, texture, and curling of their newly grown hair. These changes have not been fully explained. Topical minoxidil may shorten the duration of anagen effluvium, but its prophylactic use has not been helpful in preventing it. More studies are needed to confirm these findings. At this point, education and reassurance are the most important therapeutic considerations. Most patients will regrow their hair, and for the few that do not, other options exist. The use of hair pieces has been expanded for many medically related forms of alopecia.