Congenital insensitivity to pain and anhidrosis: a case report from South India

A Case of Generalized Xerotic Eczema in a Patient with Congenital Insensitivity to Pain with Anhidrosis

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare disease characterized by insensitivity to pain, anhidrosis, and intellectual disability. CIPA is caused by a genetic mutation in the neurotrophic tyrosine receptor kinase 1 (NTRK1) gene on chromosome 1. The anhidrosis leads to cutaneous changes such as skin dryness, lichenification, and impetiginization. Moreover, patients with CIPA may experience repeated trauma and recalcitrant eczema due to excessive scratching of wounds on their skin, because they do not feel any pain. Severe whole-body eczema in a patient with CIPA may be overlooked, leading these patients to be frequently diagnosed with atopic dermatitis and common eczema. Indeed, in patients with treatment-resistant or atypically distributed eczema and underlying anhidrosis, CIPA should be considered as a potential causative disease. Increased awareness of CIPA among dermatologists is necessary to ensure that patients receive an appropriate diagnosis. Herein, we report a rare case of generalized xerotic eczema in a patient with CIPA.

Pivotal role of the gut microbiota in congenital insensitivity to pain with anhidrosis

BACKGROUND

Increasing evidence has shown that the occurrence and development of various human diseases are closely related to the gut microbiota. We compared the gut microbial communities of human subjects with congenital insensitivity to pain with anhidrosis (CIPA) and healthy controls (HCs) to assess whether fecal microbiota transplantation (FMT) into germ-free mice and mice in acute pain influenced the behaviors of the host.

METHODS

We utilized 16 s rRNA analysis to compare the gut microbial communities of CIPA subjects and HCs and assessed whether FMT into germ-free mice and mice in acute pain influenced the behaviors of the host.

RESULTS

In a 16 s RNA analysis, the CIPA group had significant decreases in the relative abundance of 11 bacteria, whereas 7 bacteria were significantly increased. In further animal experiments, the transplantation of fecal samples from CIPA patients to healthy mice significantly increased their scores on both the mechanical withdrawal test and the tail flick test; in an acute plantar incision model, scores were also significantly increased on the mechanical withdrawal test at 4 and 5 days after the operation. Moreover, pseudo-germ-free mice receiving fecal bacteria from patients with CIPA took significantly longer to escape and had a significantly longer path length on training days 1, 2, and 5 and also had fewer platform crossings and spent less time in the target quadrant in the probe trial.

CONCLUSIONS

Our results suggest that the gut microbiota in CIPA subjects plays a key role in behaviors. Therapeutic strategies for improving the gut microbiota might alleviate CIPA symptoms.

Congenital insensitivity to pain in a 1-year-old boy

Congenital insensitivity to pain (CIP) is a rare autosomal recessive genetic condition which causes reduced pain sensation, thermal sensation, and habit of self-mutilation. It is a life-threatening condition where due to reduced pain sensation, patient might not understand the severity of the injury which can eventually lead to death. Such people live a compromised life and can also affect them psychologically. Here, we are reporting a case of an infant with clinical features suggestive of CIP with a mutation in exon 5 of PRDM12 gene. The child has minimal response to pain along with self-mutilation and mental retardation.