Genital Sores: Causes and What to Do

What genital sores look like

The appearance gives useful clues, but tests are needed to confirm:

• Blisters that burst into shallow, painful ulcers, often in clusters: herpes.
• A single, painless, firm, clean-based ulcer: syphilis (a chancre).
• Painful, ragged, deep ulcers with pus and tender glands: chancroid (rare in the US).
• Flesh-colored, cauliflower-like bumps: genital warts.
• Small, smooth, pearly bumps with a central dimple: molluscum contagiosum.
• Red, itchy, raw areas with cracks: yeast infection, eczema or friction.
• Red bumps at hair follicles: folliculitis or ingrown hairs.

STI causes of genital sores

Genital herpes

Genital herpes (HSV-1 or HSV-2) is the most common cause of genital ulcers worldwide. A first episode appears 2 to 12 days after exposure with tingling, painful blisters and ulcers, burning on urination, fever, aches and swollen groin glands, lasting 2 to 4 weeks. Recurrences are shorter and milder. Many people have very mild or no symptoms and still pass it on.

Syphilis

Syphilis causes a painless, firm ulcer about 3 weeks (range 10 to 90 days) after exposure, on the genitals, anus or mouth. It heals within 3 to 6 weeks without treatment, but the infection continues. Weeks later, a rash on the palms and soles, fever and swollen glands may appear. Untreated syphilis can damage the brain, eyes and heart. It is easily cured with antibiotics.

Chancroid and other rare STIs

Chancroid causes painful ulcers with tender, swollen groin glands that can burst. Lymphogranuloma venereum and granuloma inguinale are other rare causes, mostly seen in specific regions or networks.

Genital warts and molluscum

Genital warts from HPV are bumps, not ulcers, and are usually painless. Molluscum contagiosum causes small, shiny, dimpled bumps. Both are common and treatable.

Genital sores that are not STIs

• Friction and minor injuries: from sex, masturbation, tight clothing or cycling.
• Shaving, waxing and ingrown hairs: tender bumps or small cuts in the pubic area.
• Yeast infection and balanitis: red, itchy, sore skin on the head of the penis or vulva, sometimes with cracks.
• Skin conditions: eczema, psoriasis, lichen planus and lichen sclerosus.
• Fixed drug eruption: a sore or dark patch in the same place each time a particular medicine is taken.
• Behçet's disease: recurring painful mouth and genital ulcers.
• Lipschütz ulcers: painful vulvar ulcers after viral infections in young women.
• Cancer: rarely, a sore that does not heal can be penile, vulvar or anal cancer.

For sores specific to women, see vulvar sore.

Painful vs painless genital sores

A painless sore is easy to ignore. That is exactly why syphilis spreads, so always get a painless ulcer tested.

When to see a doctor and testing

See a doctor, sexual health clinic or STI clinic for any genital sore that is not clearly a minor injury. Avoid sex until you have been assessed. Testing usually includes:

• a PCR swab of the sore for herpes (best within the first few days) and sometimes syphilis
• blood tests for syphilis and HIV, since genital ulcers increase HIV transmission
• tests for chlamydia and gonorrhea, as STIs often occur together
• a biopsy for sores that do not heal or look unusual

You can get tested confidentially, and many clinics offer free or low-cost testing.

Treatment

• Herpes: antiviral tablets shorten outbreaks if started early. People with frequent recurrences can take a daily suppressive treatment, which also reduces transmission to partners.
• Syphilis: penicillin injection. Partners need testing and treatment.
• Chancroid: a single dose or short course of antibiotics.
• Warts: creams, freezing or removal.
• Yeast infection and balanitis: antifungal cream, good hygiene.
• Skin conditions: steroid ointments or other prescription creams.

Home comfort measures

• Bathe in plain warm water and pat dry. Avoid scented soaps.
• Wear loose cotton underwear.
• Take acetaminophen (paracetamol) or ibuprofen for pain, following the label dose.
• If urination stings, pour water over the area while urinating or urinate in a warm bath.

Preventing genital sores

Use condoms or dental dams, which lower but do not eliminate the risk of herpes and syphilis. Get tested regularly if you have new or multiple partners. Avoid sex during outbreaks. HPV vaccination prevents most genital warts and HPV-related cancers.

Frequently asked questions

What causes sores on the genitals?

The most common causes are genital herpes and syphilis. Non-sexual causes include friction, shaving, ingrown hairs, yeast infections, skin conditions such as lichen planus, Behçet's disease and allergic drug reactions. Because they can look similar, a swab and blood tests are the best way to find the cause.

Can genital sores be something other than an STD?

Yes. Many genital sores come from friction, shaving, ingrown hairs, yeast infections, eczema or psoriasis. Some recurring ulcers are due to Behçet's disease or medicine reactions. Testing is still recommended because herpes and syphilis are common and treatable.

What does a herpes sore look like?

Herpes usually starts with tingling or burning, followed by small fluid-filled blisters, often in a cluster. These break open into shallow, painful ulcers that crust and heal over 1 to 4 weeks. The first outbreak is often the worst, with fever and swollen glands.

Is a painless genital sore serious?

It can be. A painless, firm ulcer is the classic sign of syphilis, which heals without treatment while the infection progresses. A painless sore that does not heal can also rarely be cancer. Get any painless genital ulcer tested promptly.

How long do genital sores last?

A first herpes outbreak lasts 2 to 4 weeks, and recurrences 5 to 10 days. A syphilis chancre heals in 3 to 6 weeks. Minor friction sores heal in a few days. Sores lasting more than 2 to 3 weeks should be checked.