For the past two months, I ve had large mosquito bite-like inflammations on my scrotum . It doesnt hurt, but it itches and usually disappear in a couple of hours. I saw a doctor at Planned Parenthood and she said it doesn t sound like an STD. I got tested for HIV, Chlamydia and Gonorrhea and results were negative. I cant think of anything different I ve done with my hygiene. (For the record, I do have severe psoriasis all over my body, including my penis).