048 An Approach to the Diagnosis of Hair Dysplasias

J. Ferrando, R. Grimalt. Department of Dermatology, Hospital Clínic, University of Barcelona, Spain.

Clinical observation and microscopy investigation of hair shaft are the clues for the diagnosis of hair dysplasias. X-ray microanalysis and chromatography of hair aminoacids may also help in some conditions. From the clinical point of view the presence of hyperkeratosis follicularis in patients with congenital hypothrichosis focusses the diagnosis to monilethrix or keratosis follicularis decalvans. The shinning aspect of hair with the incidence of light on it suggest pili torti or pili annulati. The presence of nodes is indicative of trichorrhexis nodosa (TN), trichorrhexis invaginata (TI), trichonodosis or bubble hair. Optical microscopy is essential in current practice. Specific abnormalities are easily detected: periodic narrowing of hair/monilethrix, ringed hair/pili annulati, trichoschisis and “tiger tail” hair/trichothiodystrophy, atypical pili torti/Menkes’ syndrome, TI/Netherton syndrome, TN versus bubble hair, “ruffling”/loose anagen hair. Scanning electron microscopy allows to differenciate monilethrix from pseudomonilethrix (irregular intermitent flattening of hair), and confirms the diagnosis of woolly/curly hair conditions or pili canaliculi. SEM is also useful for the study of hair weathering and cosmetic damage. X-ray microanalysis permits to detect sulfur aminoacids deficiencies (trichothiodystrophy) and the increase of a single element (cooper/green hair). Reference: Ferrando J, Grimalt R. Atlas of Diagnosis in Paediatric Trichology. Madrid:IM&C,2000.