Ketosis-Linked Rash Sparks Doctors’ Investigation into a Mysterious Keto Side Effect
A 20-year-old man in Taiwan developed a red, itchy rash with pigmented patches after starting a ketogenic diet. Biopsy showed inflammation but no other common skin conditions, and clinicians diagnosed prurigo pigmentosa, a rare rash linked to ketosis with an unclear mechanism. Current thinking suggests high ketone levels trigger neutrophil-driven inflammation around blood vessels. Treatment: stop ketosis and give a two-week course of doxycycline, after which the rash resolved in about a week. The case highlights both potential keto-diet risks and the gaps in understanding this condition.
