Correlation between benign joint hypermobility syndrome and primary focal hyperhidrosis in children: a novel concept

Abstract
Benign joint hypermobility syndrome (BJHS) is one of the most common hereditary connective tissue disorders in children in which autonomic nervous system involvement has been reported. This study aimed to evaluate the frequency of primary focal hyperhidrosis in children with BJHS. This observational-analytical study was conducted in a case-control setting on children aged 3 to 15 years in 2018 at Mofid Children’s Hospital, Tehran, Iran. Benign joint hypermobility syndrome was diagnosed according to the Brighton criteria; then, the patients referred to a dermatologist for evaluation of hyperhidrosis. In total, 130 eligible patients with confirmed BJHS and 160 age- and sex-matched healthy subjects were enrolled in this study. Primary focal hyperhidrosis (PFH) was seen in 56.2 and 16.3% of the cases and controls, respectively, indicating a significant difference (P < 0.05). The severity of hyperhidrosis did not differ between the two groups. Although the results of the study showed a significant correlation between BJHS and PFH, more comprehensive studies are needed to confirm these findings.