Merrem's Hump-Nosed Viper (Hypnale hypnale) Bite on the Tongue of an Infant Leading to Upper Airway Obstruction: An Unusual Presentation

Abstract

Snakebites in unusual anatomical locations may lead to life-threatening consequences. Merrem's hump-nosed viper ( Hypnale hypnale) is a medically important snake in Sri Lanka and India that causes many bites and envenomings. Their bites occur almost exclusively on upper and lower limbs and commonly result in local effects, with some patients developing systemic envenoming. No antivenom is available for treating envenoming by H. hypnale. We report an unusual case of H. hypnale bite on the tongue of a 10-month-old infant resulting in rapid local swelling of the tongue and floor of the mouth, requiring prompt intervention to prevent life-threatening upper airway obstruction. Early tracheostomy prevented upper airway obstruction and, along with supportive steroid therapy and antibiotics, led to a complete resolution of the local effects of the infant without permanent disability, despite the unavailability of antivenom.