question: Help! I have urticaria on my buttocks and thighs - humidity and tight pants might be a factor. I first noticed the red irregular bumps on my buttocks about 4 years ago in the summer after returning from the beach/ pool. I continued to get it every summer since after sunbathing; it lasts for 2 to 3 weeks and then it goes away. This year however, I got it in February (I was pregnant at the time) and it's been coming back on and off in small bumps since then. I finally saw a dermatologist who did a biopsy; the diagnosis- papular urticaria. In hope for an answer, I saw an allergist as well - turns out i'm allergic to dust mites and cockroach (not known to cause hives). Yesterday I went to a hot yoga class; the room was warmer than usual and i sweated profusely. I got home and my right thigh was covered in red bumps of different sizes, some even expended into a massive red area overnight - they are somewhat itchy and my skin feels as sensitive as when I get sunburn. My left thigh is not as affected - just a few red bumps. I take Allegra on a regular basis and I used anti - itch lotion  for the first time today (Itch Fix,  i believe). I do not have any other medical condition aside from Thalassemia minor. The rash seems to have gotten worse since it first started 4 years ago, it really worries me. What else should i look into? What steps should i take?