Trichoscopy in Hair Shaft Disorders.

Area of Science:

• Dermatology
• Trichology
• Medical Imaging

Background:

• Traditional light microscopy for hair shaft analysis requires hair pulling.
• A non-invasive method is needed for accurate hair shaft examination in clinical settings.

Purpose of the Study:

• To highlight the utility of trichoscopy in diagnosing various hair shaft abnormalities.
• To describe the characteristic trichoscopic findings in specific hair disorders.

Main Methods:

• Trichoscopy involves analyzing the structure and size of growing hair shafts in their natural environment.
• Specific findings are detailed for monilethrix, trichorrhexis nodosa, trichorrhexis invaginata, pili torti, pili annulati, woolly hair, trichothiodystrophy, and ectodermal dysplasias.

Main Results:

• Trichoscopy reveals distinct features for each hair disorder: elliptical nodosities in monilethrix, nodular thickenings or fiber splitting in trichorrhexis nodosa, and telescoping in trichorrhexis invaginata.
• Pili torti show twisted shafts, pili annulati display alternating bands, and woolly hair presents with short-interval waves.
• Polarized trichoscopy is recommended for trichothiodystrophy, while ectodermal dysplasias show pigmentation heterogeneity.

Conclusions:

• Trichoscopy is a valuable, non-invasive tool for diagnosing hair shaft diseases in children and adults.
• It offers specific diagnostic criteria for a range of hereditary and acquired hair abnormalities.