It’s not uncommon to have small bumps or spots on your penis. But a painful or uncomfortable sore is usually a sign of some kind of underlying condition, such as a sexually transmitted infection (STI) or an immune system disorder.

Read on to learn more about the potential causes of penis sores and the types of symptoms that should prompt you to see a doctor as soon as possible.

Several common STIs cause penis sores. Keep in mind that many of these infections can be transmitted through close contact or sharing personal items, so even if you aren’t sexually active, they may be worth ruling out with a doctor.

Genital herpes

Genital herpes is a condition caused by infection by the herpes simplex virus (HSV). HSV infections are almost always a result of having unprotected sex with someone who’s already had an HSV infection. This is possible regardless of whether they have any visible symptoms.

An outbreak of genital herpes can cause painful, blistering, scab-like sores on your penis head, shaft, and base.

Sores can also appear on your:

  • pubic area where hair grows
  • scrotum
  • upper thighs
  • buttocks
  • mouth (if you perform oral sex on someone who has the virus)

Other symptoms of genital herpes include:

  • pain
  • discomfort
  • itchiness
  • scarring or sensitive spots left behind by popped blisters

There’s no cure for genital herpes, but you can limit your outbreaks, relieve pain and discomfort, and reduce your chances of spreading it by:

  • taking antiviral medications, such as acyclovir (Zovirax) or valacyclovir (Valtrex)
  • washing affected areas with warm water and a gentle soap
  • wearing loose cotton clothes, including underwear, pants, or shorts

Pubic lice

Pubic lice, also called crabs, are tiny insects that can grow in and feed on the area around your genitals. They can also spread to other areas covered in thick hair, such as your eyebrows or armpits.

You can get pubic lice from unprotected sex or close sexual contact with someone who has them. They can also be spread through shared clothes, towels, sheets, or blankets.

Symptoms of a pubic lice include:

  • itching around your genitals or anus that gets worse at night
  • small, bluish spots where you’ve been bitten
  • low-grade fever
  • exhaustion
  • irritability

Treatment for pubic lice may include:

  • applying over-the-counter shampoo or lotion, such as a permethrin lotion, directly to your skin and pubic hair
  • using tweezers to remove any remaining lice eggs or nits
  • vacuuming your home
  • washing all clothing, bedding, towels, and other items you’ve had contact with using hot water and bleach
  • applying prescription lotions, such as malathion (Ovide), if home treatment doesn’t work

Scabies

Scabies is caused by tiny mites digging into your skin. There, they eat your skin cells and produce eggs. They can be spread through unprotected sex as well as being in close proximity to someone who has them.

Scabies symptoms include:

  • irritation
  • itching
  • blisters, which can get infected
  • scaly, scabby skin
  • white lines where mites have dug into your skin

You’ll need a prescription-strength cream to apply to the infested area. Scabies usually requires treatment with a prescription-strength ointment.

Your doctor may also recommend antihistamines, such as Benadryl (diphenhydramine), to relieve itching or antibiotics to treat any infections resulting from open blisters.

Chancroid

Chancroid happens when the bacteria Haemophilus ducreyi, usually spread through unprotected sex, infects your genital tissues and results in sores on your penis.

Symptoms of chancroid include:

  • tiny, squishy, grayish bumps on the penis, scrotum, or surrounding areas
  • sores that open and ooze fluid or blood
  • pain around the sores
  • pain during sexual activity involving your penis or urination
  • swelling in your genital area
  • lymph node swelling that can break open your skin and cause an abscess

Treatment for chancroid includes:

  • antibiotics, such as azithromycin (Zithromax) or ciprofloxacin (Cetraxal), to destroy infectious bacteria and reduce scarring
  • surgery to drain abscesses of pus

Molluscum Contagiosum

Molluscum contagiosum happens when a poxvirus enters your skin. You can get it from having unprotected sex, skin-to-skin contact, or sharing clothes or towels with someone who has the virus.

Symptoms of molluscum contagiosum include:

  • itchy, red, painful bumps on your penis that appear alone or in clusters of 20 or more
  • open sores from scratching that can get infected and spread the virus

Some cases of molluscum contagiosum go away on their own within a few days. But others may require treatment, such as:

  • topical creams or ointments, such as podophyllotoxin cream (Condylox), to break down bumps
  • surgical removal of the bumps
  • cryosurgery to freeze off the bumps
  • laser surgery

Syphilis

Syphilis is a serious infection spread by the Treponema pallidum bacteria during unprotected sex with someone who has the infection.

Syphilis may start as a painless red, circular penis sore.

If not treated, it can eventually cause:

  • a rash that can spread to your torso, palms, and soles
  • high fever
  • swelling of lymph nodes
  • headache
  • paralysis
  • blindness

When caught early, syphilis is treatable with oral antibiotics. But more advanced cases may require intravenous antibiotics.

Granuloma inguinale

Granuloma inguinale, or donovanosis, happens when infectious Klebsiella granulomatis bacteria are spread through unprotected sex. This condition results in open sores and lesions around your genitals and anus.

There are three stages, each with different symptoms:

  • stage 1 symptoms include small pimples and pink, painless bumps
  • stage 2 symptoms include odorous ulcers surrounded by grainy tissue
  • stage 3 symptoms include deepening ulcers, which can leave scarring

You can reduce your risk of lasting scars by seeking early antibiotic treatment.

Lymphogranuloma venereum

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by Chlamydia trachomatis bacteria.

Symptoms include:

  • sores, ulcers, or bumps on your genitals or anus that can leave scars
  • swollen lymph nodes
  • rectal discharge
  • anus or rectum pain
  • feeling constipated
  • fever

Sores from LGV sometimes go away on their own without treatment. But long-lasting, painful sores usually require oral antibiotics.

While penis sores are usually a sign of an STI, other conditions can cause them as well.

Psoriasis

Psoriasis is skin condition involving an overgrowth of skin cells. It’s thought to result from your immune system mistakenly attacking healthy skin cells.

Common genital psoriasis symptoms include:

  • a rash or red bumps around your genitals
  • itchiness or discomfort around the affected area
  • dry skin that chafes and bleeds

You can try to relieve your symptoms at home by:

  • applying a cold, wet cloth to the area to relieve pain and itching
  • using topical lotions or aloe vera to soothe dry skin

If home treatment doesn’t provide any relief, your doctor may recommend:

  • treating affected skin with UV light
  • applying topical corticosteroids to reduce inflammation
  • injecting biologics, such as adalimumab (Humira)
  • taking retinoids, such as acitretin (Soriatane)

Eczema

Eczema refers to a group of skin conditions involving a rash that itches. There are several types of eczema, and many of them can affect your penis. Some cases are triggered by stress or exposure to an irritant, while others don’t have a clear cause.

Eczema rashes usually look like dry, red bumps. In more severe cases, you may also notice blisters that pop and crust over. The affected area is also usually very itchy.

You can manage mild cases of eczema by:

  • applying a cold, wet cloth to the area to relieve itching
  • using fragrance-free lotion to relieve dryness

If you regularly wash your penis with any kind of scented product, try skipping it for a few days to make sure it’s not causing your symptoms.

If home treatments don’t work, you may need to see a doctor. They’ll like prescribe one of the following:

  • calcineurin inhibitors, such as pimecrolimus (Elidel)
  • topical corticosteroids, such as hydrocortisone
  • antibiotic creams, such as mupirocin (Centany)
  • injectable medications, such as dupilumab (Dupixent)

Behcet’s syndrome

Behcet’s syndrome is a rare autoimmune condition that damages arteries and veins. This causes sores in different areas of your body, including your genitals.

Other symptoms of Behcet’s syndrome include:

  • light sensitivity
  • eye redness and swelling
  • vision problems
  • joint pain and swelling
  • abdominal pain
  • diarrhea
  • headaches

There’s no cure for Behcet’s syndrome, but several medications can help to manage symptoms. These include:

  • non-steroidal anti-inflammatory drugs, such as ibuprofen (Advil), for mild flare-ups
  • topical corticosteroids to reduce inflammation around the sores
  • colchicine (Colcrys) to relieve joint pain
  • immunosuppressive drugs, such as azathioprine (Imuran) or cyclophosphamide (Cytoxan), to help prevent your immune system from further damaging your arteries and veins

Even if the sore is small, it’s best to have it checked out by a doctor, especially if there’s a chance it could be an STI. In the meantime, avoid any sexual activity with others until you know what’s causing your sores.

Regardless of what might be causing sores on your penis, see a doctor right away or head to urgent care if you have symptoms of a serious infection, such as:

  • painful urination or ejaculation
  • sore throat
  • foul-smelling discharge
  • fever
  • chills
  • shortness of breath
  • fatigue
  • diarrhea
  • vomiting