Rash without itching may be the disease is warts, molluscum contagiosum, allergic purpura, syphilis and so on. Warts are caused by human papilloma virus infection, mainly common warts, flat warts, etc., can be manifested as a rash, usually not accompanied by itching, can be treated with laser or salicylic acid ointment and so on. Molluscum contagiosum is caused by the infectious molluscum contagiosum virus infection, visible pimples, can be treated with laser and other means. Allergic purpura, some people manifested as a painless and itchy red rash, purpura, mainly distributed in the lower limbs, pressure does not fade. Syphilis rash of stage II syphilis, may appear on the skin rose-colored red rash, painless and itchy, can be diagnosed by drawing blood to check syphilis antibody. The appearance of a rash without itching may be caused by many diseases, to go to the hospital dermatology department in time to find out the cause, and follow the doctor’s instructions for treatment.