Alopecia
Cynthia M. Moore-Sledge
Alopecia, or hair loss, is a common disorder that occurs in all age groups. Aplasia cutis and congenital triangular alopecia occur in infancy. Alopecia areata typically occurs in adolescents and young adults. Androgenic alopecia (triangular frontal recession) occurs in middle-aged men and women (1). Postmenopausal alopecia occurs in elderly patients. Of the numerous causes of alopecia, 90% of cases result from androgenic alopecia or chronic telogen effluvium. Because self-esteem and identity are linked to physical appearance, the evaluation of alopecia should be approached by the physician with thoughtfulness and concern.
Approach
Based on the pattern of hair loss, alopecia is categorized as generalized or localized. Based on scalp changes, alopecia can also be categorized as scarring or nonscarring.
A. Generalized alopecia causes include acute anagen and telogen effluvium, chronic telogen effluvium, loose anagen syndrome, and postpartum alopecia. It can also be radiotherapy-induced, cytotoxin-induced (chemotherapy, heavy metals), drug-induced (analgesics, anticoagulants, antiepileptics, central nervous system drugs, psychotropics, cardiovascular drugs, and oral contraceptives), and can result from use of immunosuppressants. Syphilis causes diffuse, patchy alopecia.
B. Localized alopecia causes include androgenic alopecia of the male variety, alopecia areata, trichotillomania (hair pulling), traction alopecia, discoid lupus, hirsutism, lichen planopilaris, pseudopelade, tinea capitis, sarcoidosis, follicular mucinosis, human immunodeficiency virus (HIV), metastatic adenocarcinoma, sclerosing basal cell carcinoma, bacterial infection, burns, herpes zoster, squamous cell carcinoma, and aplasia cutis.
C. Scarring alopecia causes include discoid lupus erythematosus, scleroderma, lichen planopilaris, aplasia cutis congenita, dissecting cellulitis, kerion, metastatic carcinoma, lymphoma, sarcoidosis, prolonged pressure, and cicatricial pemphigus.
History
Important questions to ask: What are the patient’s normal grooming habits? When was hair loss initially noted? Was hair loss gradual or abrupt in onset? Is the pattern of hair loss localized or generalized ? Are there other family members with a similar pattern of hair loss? Has there been recent psychological or physical stress? Was there exposure to radiation therapy, cytotoxic chemotherapy, or chemicals, including heavy metals?
A. Androgenic alopecia and chronic telogen effluvium are insidious in onset. Alopecia caused by radiation therapy, cytotoxic chemicals, heavy metals, or severe stress occurs almost immediately.
B. Androgenic alopecia can be localized (male pattern) or diffuse (female pattern). Diffuse hair loss is common in postpartum, radiation therapy- or chemotherapy-induced alopecia and in telogen anagen effluvium and loose anagen syndrome.
Patchy hair loss occurs with bacterial and fungal infections, discoid lupus, alopecia areata, trichotillomania, HIV, and traction alopecia.
C. Androgenic alopecia and alopecia areata have a familial predisposition.
D. Hair loss can be related to stressors such as childbirth or severe illness.
E. Chemotherapy and radiation therapy induce the rapid development of alopecia.
F. Excessive brushing or shampooing can cause hair loss. Damage to both the hair and scalp can result from the use of chemicals, tight braids, thermal heat, or rubber bands (2,3).
Physical examination
Carefully assess the scalp, hair on all body parts, and other body areas for rashes or signs of virilization. Signs of virilization include acne, hypertrichosis, clitoromegaly, frontotemporal balding, and deepening of the voice. Discoid lupus presents as scarred, patchy alopecia of the scalp and can cause loss of facial hair. Trichotillomania can involve the eyebrows and eyelashes. Frontotemporal balding is common in male pattern androgenic alopecia, whereas diffuse hair loss occurs in the female variety; both are associated with normal skin on the scalp. Tinea capitis and psoriatic alopecia should be considered with scalp flaking. “Moth eaten” areas on the scalp suggest sarcoidosis, syphilis, or discoid lupus.
The texture, length, or thickness of individual hairs may suggest the cause of alopecia. Shorter, fine hairs may be found in areas of thinning in androgenic alopecia. Trichotillomania and tinea capitis result in short broken hairs. “Black dots” occur in the lesions of tinea capitis, whereas “exclamation point” hairs occur with alopecia areata (4). Long eyelashes and straightening of scalp hair suggest infection with HIV.
Hair in loose anagen syndrome is easily removed with gentle pulling. The hair in traction alopecia and trichotillomania is firmly rooted in the scalp.
Both lichen planopilaris and discoid lupus may have associated lesions on other parts of the body, a finding that may be useful in diagnosis.
Testing
A. Laboratory tests should be based on clinical findings. Androgenic alopecia, with normal skin on the scalp of male patients, requires no further evaluation.
1. Female patients with diffuse hair loss should be evaluated with complete blood count, serum ferritin, and thyroid stimulating hormone to rule out infection, iron deficiency anemia, and thyroid abnormality. Screening tests for ovarian, adrenal, and pituitary or hypothalamic disorders include dehydroepiandrosterone sulfate, total testosterone, testosterone-estradiol binding globulin, and prolactin.
2. Tests ordered in patients with virilization are 17-hydroxyprogesterone, luteinizing hormone, follicle-stimulating hormone, and ovarian ultrasound.
3. Repeat testosterone, corticotropin stimulation tests, computed tomography of the adrenals, urinary free cortisol, dexamethasone suppression tests, adrenal or ovarian vein catheterization, and surgical exploration may be indicated if screening tests are abnormal.
4. Patient with scarred, “moth eaten” scalp lesions should have antinuclear antibodies and syphilis serology checked to rule out systemic lupus and syphilis.
5. Patients with flaking of the scalp should have potassium hydroxide examination of scalp scrapings and hair for fungal elements. Scalp scrapings or scalp hairs can be cultured for fungus or bacteria.
6. Bacterial cultures of any drainage should be obtained.
7. The gentle hair pull test is done to assess pluckability. Fewer than four hairs should be obtained per pull. Large numbers of hairs are easily plucked in loose anagen syndrome.
8. The forcible hair pluck test and trichogram assess the stages (anagen, catagen or telogen) of hairs obtained by forceful pulling of hairs with rubber-tipped forceps. These tests are best performed by the dermatologist. If a biopsy is to be done, these tests are not necessary.
B. Scalp biopsy taken with a 4-mm punch of the active area of a lesion is useful in establishing a diagnosis when the findings are equivocal; in diagnosing scarring alopecias (discoid lupus, sarcoid, lichen planopilaris, pseudopelade) or infiltrating alopecias (scleroderma, metastatic adenocarcinoma); and in distinguishing alopecias that can be similar in appearance (lichen planopilaris, pseudopelade, discoid lupus, or scleroderma). Hair samples are studied to assess follicular structure and number, the stages of the sampled hair and its structure and number. The tissue can be studied using direct immunofluorescence for evidence of an autoimmune or infectious cause (2,3).
Diagnostic assessment
Most cases of alopecia are caused by androgenic alopecia and chronic telogen effluvium. Early diagnosis and intervention can be critical in the remaining cases, if caused by metastatic adenocarcinoma, squamous cell carcinoma, melanoma, HIV, syphilis, systemic lupus, adrenal carcinoma, or a thyroid disorder. Permanent hair loss may be prevented by early institution of therapy when alopecia is caused by fungal infection or an infiltrative, scarring processes. If the offending agent is a drug (e.g., oral contraceptives, beta-blockers, antidepressants, or neuroleptics), hair loss can be reversible if the drug is stopped early in the process.
References
1. Van Neste DJ, Rushton DH. Hair problems in women. Clin Dermatol 1997;15:113–125.
2. Habif TP. Clinical dermatology: a color guide to diagnosis and therapy, 3rd ed. St. Louis: Mosby-Yearbook, 1996.
3. Sullivan JR, Kossard S. Acquired scalp alopecia. Part I: A review. Aust J Dermatol 1998;38:2207–2221.
4. Nielsen TA, Reichel M. Alopecia: diagnosis and management. Am Fam Physician 1995;51(6):1513–1522.
Book Source Details
- Book Title: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter
- Author(s): Robert B. Taylor (editor)
- Year of Publication: 2000
- Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2000 Lippincott Williams & Wilkins.
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Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2008 Williams & Wilkins.
More About Causes of Hair loss
» Next page: Alopecia/Hirsutism (Field Guide to Bedside Diagnosis)
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