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 () 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.