IL17A and Crohn disease: The association with decrease in dandruff frequency is likely to be due to true pleiotropy since Di Meglio et al [10] showed that the individuals homozygous for the Arg381Gln allele in Il23R gene were strikingly unresponsive to IL-23, with minimal or no IL-17A and IL-17F production suggesting a shared biological mechanism, and we did not observe correlation between the associated traits of dandruff frequency, Crohn’s disease and psoriasis.