Introduction to Bullous Diseases - Dermatologic Disorders - Merck Manual Professional Edition

Bullous pemphigoid is a rare autoimmune skin condition that mainly affects older adults. It happens when the immune system mistakenly attacks the layer of skin that helps hold the skin together, causing large, tense blisters filled with fluid. These blisters often appear on the arms, legs, abdomen, or groin and can be very itchy or uncomfortable. Early symptoms may look like a rash, hives, or eczema before blisters develop, which is why it’s sometimes misdiagnosed at first. While bullous pemphig