S3 SEMI-INVASIVE METHODS: THE VALUE OF TRICHOGRAMS I
Blume-Peytavi U
Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Physiology, Charité, Universitätsmedizin Berlin, Germany

Dermatologists are frequently consulted for pattern or diffuse effluvium, hair thinning, and changes in hair structure. In the diagnosis of hair diseases, clinical history and daily counting of shed hair by the patient are useful, but objective and reproducible methods are needed for exact quantification and characterization of hair loss. Studies on the dynamics of the human follicular cycle largely depend on trichogram and phototrichogram examination. The trichogram is a microscopic evaluation of plucked hairs with subsequent quantitative measuring of the number of individual hair roots, with morphological examination of each individual root. It is a helpful tool in diagnosis of hair disorders. The reproducibility of trichogram measurements depends on the maintenance of high standards in obtaining the hair samples, which has to be performed by an experienced investigator. The trichogram is a semi-invasive technique with plucking of the entire hair. This makes it unsuitable as a method for the monthly follow-up of patients, for studying the hair growth rate and the duration of the anagen phase of individual hairs and studying seasonal variations. Here non-invasive microscopic techniques such as optical microscopy with image analysers, phototrichogram, or the unit area trichogram should be chosen for this purpose. However, when correctly performed the trichogram technique is accurate and reliable for the diagnosis for hair disorders and is highly suitable because of its handiness. Although trichogram measurements are only confined to two small scalp regions, earlier studies provided evidence that, except alopecia areata, the trichogram technique of one site is representative for the neighbouring areas.