Ketosis-Linked Rash: A Rare Keto Diet Side Effect

A NEJM case report describes a 20-year-old man who developed prurigo pigmentosa, or 'keto rash,' after starting a keto diet; the itchy, net-like rash appeared on the neck and chest, is extremely rare (about 300 documented cases worldwide as of 2019), and typically resolves once ketosis ends, with treatment usually involving stopping ketosis and sometimes tetracycline antibiotics.