Herpes is a common viral infection caused by the herpes simplex virus (HSV). 18 juin 2023 ยท What are the symptoms of an STD rash on buttocks? Symptoms of an STD rash on buttocks may include itching, burning, pain, redness, and blisters or sores on the skin. How is an STD rash on buttocks diagnosed? An STD rash on buttocks is typically diagnosed through a physical exam and laboratory tests such as blood tests or swabs of the.