, gonococcal infection, herpes simplex virus, syphilis, chancroid, granuloma inguinale, lymphogranuloma venereum etc), infection in foot, sweat dermatitis on scrotum or groin, fungal infection of scrotum or groin, dermatitis in
, boils in
etc. Other than this pelvic malignancy and lymphoma could be the other causes. It is difficult to comment beyond this at this stage. Do discuss this with your doctor and get yourself examined. Take care!