Hair Loss: How to Know If Your Hair Loss Permanent or Temporary
1. Daily hair counts
Daily scalp hair counts can be useful to the physician to help quantify how much the patient is losing and make sure that this is not more than the physiologic hair loss. It is said that it is normal to loose up to 100 hairs per day. Patients are instructed to collect hairs shed in one day, count them and place them in plastic bags. All shed hairs in the shower or sink or on the brush are collected. Daily hair counts for 7 days are maintained. It is expected to loose more hairs on shampoo days (Fig. 1).
If the patient is loosing more than 100 hairs per day, the hair should be examined microscopically to detect the pathology in hair bulb and hair shaft abnormalities. Appearance of the hair bulb can distinguish between telogen effluvium, anagen effluvium and active diffuse alopecia areata.
2. Standardised wash test
In the wash test, the patient refrains from shampooing for 5 days and then he/she shampoos and rinses the hair in the basin with the hole covered by gauze. The hairs remaining in the water and the gauze are collected and sent for examination. Hairs must be counted and divided into ≤3cm and ≥5 cm in length. This is an important technique to differentiate telogen effluvium from female-pattern hair loss. The 'modified hair wash test' demonstrates that in FAGA 58.9% of hair is vellus, whereas in chronic telogen effluvium (CTE), there are only 3.5%.
3. 60-S hair counts
The technique comprises of the following four steps:
1) Before shampooing, comb your hair for 60 s over a pillow or sheet of contrasting color to your hair, starting with the comb at the back top of the scalp and moving the comb forward to the front of the scalp.
2) Repeat the procedure before three consecutive shampooings (e.g., if you shampoo every other day, then repeat the procedure every other day) and always use the same comb or brush.
3) Count the number of hairs in the comb or brush and on the pillow after each hair count and record.
4) Repeat the above procedure monthly and bring the results to your dermatologist.
Merits and demerits (daily hair counts, wash test, 60-S hair counts)
Performing a hair count is tedious and time-consuming for the patient. But, it is something patients can do on their own and monitor their progress. The method is very subjective and it is usually difficult to come to a certain diagnosis. The number-100-is arbitrary. No clinical study or standardized method has validated the number 100. Whether 100 pertains to both men and women and whether or not the hair shedding changes with age has also not been established. In personal observation, various estimates for normal hair shedding have ranged from 10 to 250!
In a study of 404 females without hair or scalp disease, daily lost hair was collected over 6 weeks, where the mean hair loss rate was found to range from 28 to 35 per day. Also, fewer than 50 hairs can be significantly abnormal in a patient having lost 50% of his/her hair volume.
Diagnostic definitions for cut-offs cannot be established for wash test as vellus hair count on the surface does not correlate with actual vellus hair counts (on scalp biopsy), as many vellus hair follicles fail to reach the scalp surface.
It is cumbersome for the patient to abstain from shampooing for 7 days.
We advise daily hair collection over 4 days after last shampooing in our center. Also, daily hair counts more than 70 are further probed into.
Falsely elevated numbers in 'daily hair counts' and the '60-s hair counts' tests could be due to hair breakage during combing.
These techniques, although easy to perform and inexpensive, are neither standardized nor diagnostic. They however give the clinician an estimate of the amount of hair shedding. Also, the 60-s hair counts cannot adequately measure the number of hairs shed from the lateral and posterior portions of the scalp.
4. Pull test
This is also known as the 'traction test' or 'Sabouraud's sign' or the 'pull-out sign.'
Approximately 20-60 hairs are grasped between the thumb, index and middle fingers from the base of the hairs near the scalp and firmly, but not forcefully, tugged away from the scalp. If more than 10% hairs are pulled away from the scalp, this constitutes a positive pull test and implies active hair shedding. The patient must not shampoo for at least a day prior to the pull test (Fig. 2).
Merits and demerits
This test is based on the concept of 'gentle' pulling of the hair to bring about shedding of telogen hairs. It helps to assess the severity and location of hair loss. The test is positive in cases of telogen effluvium, anagen effluvium, loose anagen syndrome, early cases of patterned alopecia and at the advancing edge of alopecia areata. In cases of acute telogen effluvium, the pull test is positive over the entire scalp whereas in cases of AGA, it could usually be positive over the area of thinning.
The extraction of anagen hairs with thickened root sheaths strongly suggests cicatricial alopecia, even if the pull test does not reveal increased hair loss. Therefore, even though only a few hairs may be extracted, the pull test is always regarded as pathological if anagen hairs are present.
Hair pull tests vary from person to person. It is a very rough method and difficult to standardize as it is subject to so much interindividual variation among investigators. The pulling force is not distributed uniformly all over the whole bundle, which creates variation in the pulling force from one hair to another. It is also difficult to approximate the number of hairs grasped, thereby leading to false inference of the test. Moreover, negative tests do not exclude the diagnosis.