Sore, red or rash on the penis after sex: common causes

A red penis, a rash or a sore penis after sex is unsettling, and the possible causes range from rubbing and a reaction to a condom or lubricant to thrush and sexually transmitted infections (STIs). A few need help quickly. The NHS says not to try to diagnose lumps or spots on your penis yourself, and to get medical help, so use what follows to know what to mention, not to rule things out.

Why is my penis red or sore after sex?

Rubbing during sex can irritate the skin of the penis, NICE's guidance for GPs says, and so can a reaction to latex condoms, lubricants or soap. Sex can also trigger thrush, and STIs are passed on during sex. A tight frenulum can tear, and a skin condition such as lichen sclerosus can make sex sore. When the head of the penis is inflamed, doctors call it balanitis.

Sore, red or a rash after sex: what it might be

	What you might notice.	How it links to sex.	Who can help.
Rubbing (friction)	A sore, red, sometimes swollen head of the penis	Rubbing during sex can irritate the skin and cause balanitis	A GP or sexual health clinic
Irritation or allergy	Burning or itching, with a red, scaly rash on the head of the penis and some swelling	Latex condoms, lubricants and soap can trigger it, usually within a few hours or days	A GP or sexual health clinic to check a rash; a pharmacist can help with contact dermatitis
Thrush	Irritation, burning and redness around the head of the penis and under the foreskin; a white discharge like cottage cheese	Not an STI, but sex can trigger it and, less often, pass it on	A GP or sexual health clinic the first time; a pharmacist after that
An STI, such as herpes or chlamydia	Blisters or sores, a rash, an unusual discharge, or pain when peeing	Passed on during sex; symptoms can take days, weeks or longer to appear	A sexual health clinic
A tight or torn frenulum	Pain during an erection or sex; a tear that bleeds	A tight frenulum may tear during sex	A GP if it keeps happening or doesn't go away
Lichen sclerosus	Itching, burning or soreness, especially during or after sex; skin that tears and bleeds; a foreskin that gets tighter	A long-term skin condition, not an infection, and it can't be passed on	A GP, who may refer you to a dermatologist
Penile fracture (an emergency)	Losing the erection straight away, bruising and swelling, sometimes with a snapping or popping sound	Damage to the erect penis during sex or from forced bending	A&E straight away

Several of these can look alike, and the NHS advises getting lumps, spots or a rash on the penis checked rather than diagnosing them yourself. Sources: NICE CKS, NHS, BASHH, BAD and BAUS.

Can rubbing during sex make your penis sore?

Yes. NICE's guidance lists irritation during sex among the causes of balanitis, and the British Association for Sexual Health and HIV (BASHH) lists trauma among them too. The NHS describes balanitis as a swollen, itchy, sore head of the penis that usually looks red, though this may be less obvious on brown or black skin. Washing too often can irritate the skin as well, according to NICE.

If you use lubricant with latex condoms, the NHS says not to use an oil-based one: use a water-based or silicone-based lubricant instead. If the rubbing is on your inner thighs or in your groin rather than on your penis, our guide to groin chafing covers that.

Penis rash after sex: could it be a condom or lube allergy?

It could be. NICE's guidance lists latex condoms, lubricants, soap, bubble bath and fragrances among the triggers of irritant or allergic contact dermatitis on the penis. Irritation tends to cause pain and burning, and an allergy tends to cause itching, with a red, scaly rash on the head of the penis and some swelling that lingers or keeps coming back.

The NHS says contact dermatitis usually appears within a few hours or days of contact with the trigger, and that the best way to prevent it is to avoid whatever causes it. A few practical points from the NHS:

• If you have a latex allergy, don't use latex condoms. Latex-free condoms are available, and the packet says what a condom is made of.
• With a sore, inflamed head of the penis, the NHS suggests condoms for sensitive skin.
• For contact dermatitis in general, the NHS says to speak to a pharmacist if it's troubling you and to see a GP if it's persistent, keeps coming back or is severe. For a rash on the penis, the NHS advice is to see a GP or go to a sexual health clinic.

If the trigger can't be found, a GP may refer you to a dermatologist for further tests, the NHS says. NICE's guidance suggests this referral for patch testing when an allergy is suspected.

Can you get thrush from sex?

Sex can trigger thrush and, less often, pass it on, the NHS says, though thrush isn't classed as an STI. In men it causes irritation, burning and redness around the head of the penis and under the foreskin, sometimes with a white discharge like cottage cheese, an unpleasant smell or a foreskin that's hard to pull back. BASHH notes a high rate of thrush in the sexual partners of men who have it. Our guide to thrush in men covers the symptoms and the treatments a pharmacist or GP can give you.

Could it be an STI, and what are the signs?

Sometimes. STIs are passed on during sex or sexual contact, and many have no symptoms, so the NHS says the only way to know for sure is to get tested. The symptoms it lists include:

• an unusual discharge from your penis
• pain when peeing
• lumps or skin growths around your genitals
• a rash
• itchy genitals
• blisters, sores or warts around your genitals

Two to know about:

• Genital herpes causes small blisters that burst to leave red, open sores, with tingling, burning or itching, the NHS says. Go to a sexual health clinic as soon as possible: antiviral medicine needs to be started within 5 days of symptoms appearing to stop them getting worse.
• Urethritis, often caused by an STI such as chlamydia, causes pain or burning when you pee, a white or cloudy discharge and an irritated or sore tip of the penis. When an STI is the cause, symptoms can take a few days or weeks to appear after sex.

STIs can take up to 7 weeks after unprotected sex to show up on a test, so if you don't have symptoms, the NHS says it's best to wait 7 weeks before getting tested. Until you've been checked, don't have sex, including oral sex, without a condom or dental dam.

What if the skin tears during sex?

A tight frenulum, the band of tissue on the underside of the head of the penis, can cause pain during an erection or sex and may tear, causing bleeding and discomfort, according to the British Association of Urological Surgeons (BAUS). Our guide to a torn or tight frenulum covers what to do.

If the skin keeps tearing and bleeding during sex, or your foreskin is getting tighter, see a GP. The British Association of Dermatologists (BAD) says both can happen with lichen sclerosus, a long-term skin condition that isn't an infection and can't be passed to a partner. Our guide to a tight foreskin covers the foreskin side.

Which pain after sex needs urgent help?

Three problems need hospital care straight away, according to the NHS and BAUS: a suspected penile fracture, a foreskin stuck behind the head of the penis, and an erection lasting more than 3 to 4 hours. Hot, painful, swollen skin needs an urgent GP appointment or NHS 111.

• Losing the erection straight away, with bruising and swelling and sometimes a snapping or popping sound, can mean a penile fracture. BAUS says the penis can be damaged during sex or by forced bending when erect, and advises urgent repair wherever possible, because treating it without surgery carries a higher risk of erection problems and deformity. Go to A&E, the NHS service for serious injuries.
• A foreskin pulled back that won't go back over the head of the penis (paraphimosis) is a medical emergency, the NHS says: call 999 or go to A&E.
• An erection that lasts more than 3 to 4 hours (priapism) can cause permanent damage if not treated quickly: call 999 or go to A&E.
• Skin that's painful, hot and swollen can be a sign of a skin infection (cellulitis): ask for an urgent GP appointment or get help from NHS 111.

If you're not sure whether you need A&E, NHS 111 can check your symptoms and tell you what to do.

What helps while it settles?

For a sore, inflamed head of the penis, the NHS advises washing every day with just water or an emollient (a moisturising treatment), gently pulling back the foreskin to wash underneath with warm water, drying gently, and not using soap or shower gel. NICE's guidance adds avoiding any suspected trigger, such as a particular condom, lubricant or soap.

Treatment depends on the cause, the NHS says. In NICE's guidance an antifungal treats thrush and a mild steroid such as hydrocortisone treats irritated skin. The NHS advises seeing a GP to find out what's causing a swollen, sore head of the penis.

On sex while it heals, the NHS advice depends on the cause: with thrush, avoid sex until it has cleared if sex is uncomfortable; with a possible STI, don't have sex without a condom until you've been tested; with herpes, don't have sex until the sores have gone.

When should you see a GP or a sexual health clinic?

The NHS says to see a GP or go to a sexual health clinic if:

• you have a lump, sore or ulcer on your penis
• you have a rash or spots on your penis
• the tip of your penis is swollen, itchy, sore and red
• you notice any changes to how your penis looks
• you have symptoms that are not going away

Go to a sexual health clinic (also called a GUM clinic) if you think you might have an STI or a partner has symptoms of one. These NHS clinics are free and confidential, you don't usually need a GP referral, and they won't share what you discuss with your GP without your permission. You can ask to see a male or female doctor or nurse.

Try not to be embarrassed. The NHS points out that doctors and nurses are used to talking about these symptoms.