Early clinical diagnosis of congenital insensitivity to pain with anhidrosis in an infant: a case report.

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare autosomal recessive disorder. Its core clinical manifestations include profound pain insensitivity, generalized anhidrosis, and subsequent recurrent hyperthermia. To date, only a few hundred cases have been reported in the literature. An 8-month-old female infant was admitted with a 14-day history of recurrent fever that was unresponsive to systemic antimicrobial therapy. Dynamic clinical monitoring revealed an environment-dependent body temperature. Physical examination showed dry and coarse palms, accompanied by painless oral ulcers and painless distal finger injuries. Retrospective history taking confirmed a lack of sweating during febrile episodes and an absence of pain perception. Whole-exome and Sanger sequencing identified compound heterozygous variants in the NTRK1 gene, comprising a maternal intronic variant (c.851-33T > A) and a paternal large deletion at 1q23.1 encompassing exons 5-7. A definitive clinical diagnosis of CIPA was established. In infants presenting with refractory fever, clinicians should maintain a high index of suspicion for non-infectious etiologies. Early evaluation for anhidrosis and pain insensitivity, along with the inclusion of CIPA in the differential diagnosis, can expedite definitive diagnosis, prevent secondary injuries, and facilitate timely genetic counseling.