For the past several months, I’ve been getting itchy, raised welts that seem to come and go unpredictably. Some days they appear within minutes, especially in the evenings, and other days I wake up with them already on my arms or torso. The itching can be intense—sometimes it feels like a warm, prickling sensation under the skin that makes it difficult to focus. The welts usually fade within a few hours, only to show up somewhere else. It’s been frustrating and disruptive to daily life.