A 4 mm punch biopsy sectioned horizontally will show a normal terminal:vellus hair ratio of 8:1 to 9:1 in patients with chronic telogen effluvium whereas in female pattern hair loss the ratio is 2:1.
"With all the other significant medical illnesses that may be affecting an older individual, hair loss may seem trivial in comparison. However, if the hair loss is important to the patient, then it should be considered important by the dermatologist," notes Dr. Miller, who is associate professor of dermatology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, Pa.
Female pattern hair loss, involutional alopecia, acute and chronic telogen effluvium and postmenopausal frontal fibrosing alopecia are five hair loss disorders that occur in the older population. Diagnosis can often be based on the clinical findings and history, although biopsy may be considered, most commonly for distinguishing female pattern hair loss from involutional alopecia and also for determining prognosis by answering the question of whether permanent destruction of hair follicles has occurred.
Female pattern hair loss affects about half of women aged 50 years and older.
Its diagnosis is suggested by the presence of a widened part width on the crown of the scalp relative to the occiput accompanied by retention of the hairline. However, a Christmas tree pattern, in which the part width fans out as it approaches the frontal hairline, is also seen relatively frequently.
Topical application of minoxidil 2 percent solution is the only Food and Drug Administration (FDA) approved treatment for female pattern hair loss. However, early detection is important because it is seems to be associated with the best outcome.
"The majority of patients who use minoxidil will at least maintain their existing hair, and that may be a reasonable goal of treatment, while about two-thirds will have visible improvement. However, the latter patients are usually those whose hair loss is caught early, and it is important to take a photograph of the midline part to document that improvement," Dr. Miller says.
When a woman in her 50s complains about recent onset of diffuse hair thinning, but the part widths are equal on the crown and occiput and there is not increased shedding, involutional alopecia is the likely diagnosis.
Caused by follicular senescence, involutional alopecia may be distinguished from hereditary hair thinning through a biopsy that will show a normal ratio of terminal to vellus hairs.
Management of involutional alopecia consists primarily of reassurance. In addition, periodic photographic follow-up is recommended for early detection of onset of female pattern hair loss.
"Involutional alopecia is a condition that we really need to learn more about. There is no known effective treatment to offer, but patients can be told they likely are experiencing age-related thinning that will affect the entire scalp and that they will not go bald," Dr. Miller says.
Acute telogen effluvium
Acute telogen effluvium is characterized by acute onset of hair shedding, and not uncommonly, affected individuals bring with them a small plastic bag or envelope filled with collected lost hair.
The temple region is often affected most severely, and the part widths will be equal on the crown and occiput. A positive pull test, defined as obtaining more than two or three telogen hairs, also supports the diagnosis.
There are several possible etiologies for acute telogen effluvium in older patients, including acute illness, recent surgery, thyroid disease and various medications. In women, the hormone replacement therapy product containing esterified estrogens and methyltestosterone (Estratest) may also promote hair loss, as it causes an increase in testosterone levels.
"Rather than order a battery of tests, taking a good history can identify an underlying cause. Then patients can be reassured that the condition is reversible and they will not go bald," Dr. Miller says.
He adds that while there are some anecdotal reports that topical minoxidil solution is effective for this hair loss disorder, he rarely prescribes it.
Chronic telogen effluvium
Chronic telogen effluvium usually develops during the fourth to sixth decades of life.