Reviews

Diffuse hair loss: Its triggers and management

Author and Disclosure Information

 

References

PHYSICAL EXAMINATION

Given the complexity of the diagnosis of diffuse hair loss, the clinical examination is of great importance. The scalp should be examined for degree and pattern of hair loss. The hair shafts should be assessed for length, diameter, and breakage.21 The scalp should be examined for inflammation, erythema, and scaling.21

The hair-pull test should be done in all patients with hair loss.22 This involves gentle traction from the base to the tips of a group of 25 to 50 hairs. Normally, only 1 or 2 hairs are dislodged.1 However, in shedding conditions, 10 to 15 hairs can be dislodged.1 Light-microscopy helps differentiate the pulled hairs into telogen hairs or dystrophic anagen hairs.1 Hair shaft microscopy can also indicate nutritional deficiencies.11

A daily count of shed hair can sometimes be useful,22 as can a hair collection.7 A hair collection is done by the patient at home over 2 weeks.7 The shed hair is collected daily at one specific time, usually in the morning, and is placed in dated envelopes. It is important to note the dates of shampooing.7 Daily hair collections of more than 100 hairs per day suggest effluvium.7 Hairs can then be examined and identified as telogen hairs or anagen hairs.

LABORATORY EVALUATION AND SCALP BIOPSY

A laboratory workup can identify triggers or causes of diffuse telogen hair loss. This should include the following:

  • A complete blood count and serum ferritin level to look for anemia and iron deficiency
  • A thyroid-stimulating hormone and thyroxine (T4) level to detect thyroid disease
  • A serum zinc level to detect zinc deficiency
  • A comprehensive metabolic panel to exclude chronic renal or liver disease.

If the history and physical examination suggest lupus erythematosus or syphilis, serologic testing can be ordered. Also, an androgen screen should be performed if signs of hyperandrogenism are present18 or if a hormonal cause for the telogen hair loss is suspected.

Scalp biopsy is helpful in most cases of hair loss.21 Lack of identifiable triggers, chronic hair loss, miniaturized hair shafts, and failure to exclude alopecia areata are all indications for scalp biopsy.1,2

Two 4-mm biopsy specimens are recommended to provide for adequate horizontal and vertical sectioning.7 Terminal and vellus hair counts can be done, and the anagen-to-telogen hair ratio can be calculated. In acute telogen effluvium, a reversal of the normal anagen-to-telogen ratio can be seen.23 Miniaturization of the hair shafts and low terminalto-vellus hair counts are seen in androgenetic alopecia.23 Characteristic peribulbar lymphocytic inflammation can be seen in alopecia areata.20

MANAGEMENT: THE IMPORTANCE OF PATIENT EDUCATION

The most important aspect in the management of telogen effluvium is educating the patient about the natural history of the condition. The normal hair cycle should be explained, as well as the relationship between triggers and the timing of hair loss. For example, in telogen effluvium, shedding usually is noted 2 to 3 months after a trigger, although it can in rare cases begin as soon as 2 weeks after a trigger.7

To help identify triggers, a health diary or calendar can be useful. The patient should be instructed to record any stresses, hospital admissions, surgical procedures, new medications, dosage changes, or other potential triggers of hair loss.1,7

The patient should understand that, once the trigger is identified and removed or treated, the shedding settles but can continue for up to 6 months.1 Regrowth can be noted 3 to 6 months after the trigger has been removed, but cosmetically significant regrowth can take 12 to 18 months.1,7

In acute telogen effluvium, if the trigger can be identified and removed, the shedding is short-lived and no further treatment is required.1,4 Patients can be reassured that they are unlikely to go bald.

Adequate nutrition is essential. If a drug is suspected, it should be ceased or changed for at least 3 months to determine whether it is a contributing factor.3 Any underlying scalp inflammation (for example, seborrheic dermatitis or psoriasis) should be treated with an anti-dandruff shampoo and a topical corticosteroid. 1,7

Chronic diffuse telogen hair loss is more complex because multiple sequential or repetitive triggers can be involved.7 Nutritional deficiencies, thyroid disease, systemic illnesses, and infections should be treated.

For acute telogen effluvium, chronic diffuse telogen hair loss, and chronic-repetitive telogen effluvium, biotin and zinc replacement can support hair regrowth.1,7

No specific medical treatment exists for telogen effluvium, but applying the topical hair-growth promoter minoxidil (Rogaine) 2% and 5% to the scalp once a day can be useful in chronic diffuse telogen hair loss and chronic telogen effluvium7 (W. F. Bergfeld, personal communication, November 12, 2008).

In men, medical treatment of androgenetic alopecia includes topical minoxidil 2% or 5% and oral finasteride (Propecia).18 Women can also use topical minoxidil; however, only the 2% solution is approved by the US Food and Drug Administration for female androgenetic alopecia.18 Antiandrogens such as spironolactone (Aldactone) are used off-label for females with androgenetic alopecia. Antiandrogens cause feminization of the male fetus; hence, all women of childbearing years should be on a reliable form of contraceptive.18 Small studies show spironolactone combined with an oral contraceptive can be useful in the treatment of androgenetic alopecia in women.18,24

Anagen hair loss is usually managed with observation and support, as the cause will be obvious from the history. If no iatrogenic cause can be found for anagen hair loss, then other causes such as alopecia areata and heavy-metal poisoning should be investigated and the underlying condition treated.

Next Article: