Hi Doctor, I am a gay man and recently had sexual activities with several men lately, a combination of unprotected oral sex and protected anal sex. I noticed insect bites and red spots on my body, along pubic area, so made me think I had pubic lice . I used Permethrin 5% and they seem to have disappeared now. However, my concern is that from today I started experiencing sore legs and painful knees on the left side and also slight discomfort around my testical area. Its been 3 days since the last sexual partner, and I know you can t diagnose without seeing the patient, but what do you think it could be?