TrichoScan : combining epiluminescence microscopy with digital image

EJD n° 4, vol. 11, July-August 2001 Hair loss or hair thinning is a common complaint in clinical dermatology and patients seeking advice for hair loss are not necessarily bald. In established cases of androgenetic alopecia (AGA) characteristic patterns are easily discernible. However, especially in females the clinician is often challenged by patients with initial stages of AGA where hair loss is reported but alopecia is not recognizable or the effect of treatment attempts are hard to measure. Consequently, there is a need for a sensitive tool to monitor hair loss and treatment response. Numerous methods have been reported [1] to assess the rate of hair growth. The techniques can be classified as either invasive (e.g. biopsies [2, 3]), semi-invasive (trichogram [4, 5], unit area trichogram [6]) or non-invasive (e.g. global hair counts [7], phototrichogram [8-13]) methods. Quantitative methods for the analysis of human hair growth and hair loss are necessary to determine the efficacy of hair promoting drugs, and while reviewing the capabilities of the different methods, the common theme emerges that most techniques are of little use to the clinician because they are time consuming, often costly or difficult to perform [14, 15]. Therefore, an operatorand patient-friendly, inexpensive, validated and reliable method is a rational need. Such a method must be able to analyze the biological parameters of hair growth, which are: 1: hair density (n/cm2), 2: hair diameter (μm), 3: hair growth rate (mm/day) and 4: anagen/telogen ratio. This paper describes the TrichoScan as such a method which combines standard epiluminescence microscopy (ELM) with automatic digital image analysis for the measurement of human, and potentially animal hair, in situ. The application of the technique is demonstrated by comparison of the aforementioned hair parameters of individuals without apparent hair loss with men with untreated AGA and men after treatment with finasteride (1 mg/day).