Methods of hair loss evaluation: a comparison of TrichoScan(®) with the modified wash test

The reliability of the methods currently used for diagnosing hair loss is ill defined. We studied 41 subjects complaining of hair loss, including androgenetic alopecia and telogen effluvium, and compared the results obtained with the modified wash test (MWT) and TrichoScan(®) . Data were analysed statistically with the t-test and the Cohen κ statistic. The concordance between the clinical diagnosis and that of MWT (5% cut-off) was fair (κ = 0.32) and that between clinical diagnosis and TrichoScan(®) was still fair though less satisfactory (κ = 0.22). Only in 17 patients (41%) were the MWT and TrichoScan(®) diagnoses concordant. MWT was better in general and especially at detecting telogen effluvium (TE) (29% vs 19%). In conclusion, the clinical observation should be assisted by MWT and dermoscopy, leaving the biopsy for very difficult cases. TrichoScan(®) is less useful and may be even misleading in TE.