Update on Detection, Morphology, and Fragility in Pili Annulati in Three Kindreds

The study examined 11 cases of pili annulati from three families using clinical assessments and various microscopy techniques. Light microscopy with a fluid mountant was found to be more sensitive than clinical examination, increasing detection by 120%. The characteristic periodic bands of pili annulati were less frequent distally in the hair shaft, and weathering features were observed in two cases, indicating that pili annulati can weaken hair. Amino acid analysis showed elevated lysine and decreased cystine in affected individuals compared to controls, suggesting a reduced threshold for weathering. The study concluded that careful light microscopy is essential for detecting mild cases, and the expression of the phenotype varies widely among individuals and within individual hairs.