Congenital Insensitivity to Pain With Anhidrosis Is Associated With Harlequin Color Change: A Survey Study.

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy (HSAN) type IV, is an extremely rare autosomal recessive congenital condition characterized by the loss of sensation to pain and absence of sweating with one case report linking this with harlequin color change. To explore the relationship further, we developed a survey using the Research Electronic Data Capture software and distributed it to families and others with close relationships and knowledge of patients with CIPA. Our results indicate that harlequin color change, characterized by unilateral flushing of the face and/or body, was significant and noted by all respondents as being present early in the condition appearing around the same time as first symptoms and around or before diagnosis of CIPA. Future clinicians should be aware of this dermatological phenomenon and its potential association with CIPA patients, especially during early disease manifestation where diagnosis can be difficult.