Rashes are often the first symptoms of a sexually transmitted disease (STD). The most common STDs cause pain, discharge, and itching, along with redness and sores. Doctors use various tests to diagnose them, including visual observation of STD rashes, urinalysis, and blood samples.
One of the most obvious STD rashes is caused by syphilis. The disease first begins with a chancre, a painless sore that goes away without treatment, usually found on the genitals. A spotty rash then appears and can do so on any part of the body. The palms of the hands and the bottoms of the feet are common places to find it. Syphilis is easily cured with penicillin, but if not treated it will eventually cause heart disease, blindness, and dementia.
STD rashes with blistering, painful sores may be genital herpes. The herpes simplex II virus is similar to that which causes cold sores, and the rash is comparable. A fever and fatigue may occur during an outbreak. Initial infection often causes the most severe symptoms. The virus is active even when the sores are not present, making the disease extremely contagious.
Genital warts cause unsightly rashes. Pink, soft growths appear on the penis or anus, and both around and in the vagina. They are caused by the human papilloma virus (HPV), certain strains of which can lead to cervical cancer in women. A vaccine for this virus is available and is recommended for females aged 9-26 years. Males in the same age group can take a variant that protects them against genital warts.
Scabies is not an STD but is often mistaken for a rash caused by an STD. It is the result of infection by a mite that burrows under the skin, resulting in severe itching, redness, and lines on the skin that resemble pencil marks. The mite spreads through close personal contact, including sex. Scratching can break the skin and sores may appear. The infection is treated with creams, and all bedding and clothing should be laundered in hot water to kill the mites.
The presence of STD rashes indicates the need for tests to determine which disease may be present. Diagnosing an STD can be done through blood or urine tests, and in some cases a swab is taken from the affected areas. HPV and chlamydia tests are performed by direct sample of cells from the cervix in women. They can be done at the same time as a Pap smear during an annual pelvic exam.