Trichometry helps to assess the intensity of hair loss, make a differential diagnosis between Telogen and Androgenetic Alopecia. TrichoSciencePro © computer program employs Trichometry calculations per hair wash test and growing hair test results.
In preparation for the hair wash test the patient should not wash hair for 5 days. Prior to hair wash the sink waterdrain shall be covered with a gauze. After hair wash collect all the hairs remaining in a gauze and place them on a sheet of white paper. Count the total number of washed hair while paying attention to their lengths and dividing them into 3 groups of up to 3 cm, 3 to 5 cm and over 5 cm in length. Hairs less than 3 cm in length are usually Vellus-like hairs, their diameters are less than 30 microns. Normally, the number of washed out hairs may be from 200 to 250 hairs. In Androgenetic Alopecia number of Vellus-like hairs is usually above 10% of total count, in Telogen Alopecia - less than 10%, while the total number of hairs in AGA is usually no more than 100 hairs and with Telogen Alopecia exceeds 250 hairs. When counting, it should be noted that some broken long hairs or hairs with blunt angle, which were trimmed to this length during haircut, may be among short hairs, therefore these hairs shall be considered as long hairs. It is impractical to carry out this test if the length of patient's hair is less than 6 cm. The drawback of this method is that the efforts applied to diferrent scalp sites during hair wash can be different, it also depends on the intensity applied by patient during daily hair brushing prior to the test.
In order to perform the growing hair test, few hair strands shall be cut off at their "roots" as close to scalp as
possible, and then stuck on to a slide with see
through sticky tape, ususally double-sided scotch tape. Next count hair fibers, then take a ruler and measure the
lengths of each hair fiber. For example, there were 100 hair fibers cut
off and out of them 10 are 1-2cm, 15 - 2-3cm, 20 - 3-4cm, 25 - 4-5cm
and remaining 30 hair fibers are longer than 5 cm. It is assumed, that
1-2cm long hair fibers grew out 1-2 months ago, practically immediately
replacing the lost 1-2 month ago hair fibers, which opened them up a
space. And 2-3cm long hair fibers grew out 2-3 months ago replacing the
lost 2-3 month ago hair fibers, etc. Therefore, if out of 100 hair fibers in
our example 10 are 1-2cm long, this means that 1-2 month ago the hair
loss resulted in 10% of a total scalp hairs, 2-3 month ago the hair loss resulted in 15% of a total scalp hairs and so on. If the counting is done in February and patient has 100 000 hairs, the calculator will estimate, that in December-January patient has lost 10,000 hairs, November-December - 15,000 hairs and so on. This estimation is good for Terminal hairs counts for Androgenetic Alopecia and Telogen Alopecia, but can not be applied for Alopecia Areata and Cicatricial Alopecia. It also cannot account for a loss of Vellus hairs, since lost Vellus hairs are not always replaced with young hairs or their growth may be delayed. Also it shall be noted, that if patient has more than one "yellow dot" or "white dot" in any field of view in Trichoscopy session, that means a presence of some substantially delayed new hair growth and conduction if this test is considered to be impractical.
For more Trichometry features of the TrichoSciencePro © computer program refer to Chapter 16. "Hair Calculator module. Trichometry functions." of the User Manual. In case of any recent updates, for some additional information please also refer to the publication for the New Version.