Red Sore On Penis – What Could It Mean?

We break down the potential sexual health causes

If you notice a red sore on your penis, it can often be concerning and embarrassing. There are a number of potential causes, all of which have subtle differences in appearance, but major differences in prognosis and treatment. We’ve broken down the potential causes of any red sores that may appear on your penis.

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What could this red sore on my penis be?

There are a number of conditions which can cause a red sore to appear on the penis or on the skin surrounding the penis. We’ve outlined some of the potential conditions below, but the only way to know for sure what’s causing the sore is by carrying out an STD test.


There are two forms of herpes simplex virus that could potentially be causing a red sore on your penis, including herpes simplex 1 and herpes simplex 2. The herpes virus usually presents in the form of red sores or blisters affecting either the face or genital region. These can be incredibly painful, with outbreaks lasting as long as three weeks.

Herpes Simplex 1 (HSV1)

This strain of herpes generally affects the mouth and is often referred to as oral herpes. HSV1 will usually present in the form of cold sores and can be passed on through kissing or sharing drinks. It can however be passed on to the genital region if someone who has an active cold sore performs oral sex on someone.

Herpes Simplex 2 (HSV2)

This strain is usually the cause of herpes sores that would affect the penis or genital region. More commonly known as genital herpes, HSV2 causes outbreaks of red sores that are similar to cold sores, but they are usually smaller and cover a bigger area. They also often present as multiple sores whereas oral herpes will usually only have one sore. It can be extremely uncomfortable and will remain contagious until the sores have fully healed.


Another sexually transmitted infection that can cause a red sore on the penis is syphilis. One of the first signs of syphilis is a red, but painless sore known as a chancre. It can appear on any area where you’ve had sexual contact with an infected individual. It’s often an open sore, yet due to its pain free nature it may go unnoticed.

In the initial stages of syphilis there are very few symptoms other than the sore, which is similar to herpes. You may however notice swollen lymph nodes, particularly in the groin area. Once the sore disappears there are no further symptoms of syphilis until it progresses to secondary syphilis. Secondary syphilis has flu like symptoms and a severe looking skin rash, this will usually occur 4 – 10 weeks following the passing of primary syphilis.

Genital Warts

The other potential cause of the red sore on your penis is genital warts. Genital warts are caused by the human papilloma virus, the same virus that causes normal warts. Indeed, genital warts look like normal warts, with the only difference being that they affect your genital region. These warts are usually completely painless, but there may be multiple appear over time as they come into contact with other areas of skin.

Unfortunately genital warts are contagious and they can be passed on to sexual partners if your skin touches theirs. They’re difficult to prevent, especially if a condom doesn’t cover the area affecting the warts. Unfortunately it’s difficult to test for genital warts because there are so many strains of the HPV virus, therefore diagnosis is usually completed through a physical inspection.

As mentioned, the HPV virus has many strains. Some strains are known to cause cell mutations in the cervix which can present a cervical cancer risk over time. Thankfully, the strain of HPV that causes genital warts is not linked to cervical cancer and doesn’t present a risk factor.

How to treat the red sore on the penis?

The treatment that can be offered to heal any red sores affecting the penis or genital region will depend on the cause. Often it’s necessary to be tested for syphilis and herpes together in order to fully ensure that the correct medication can be offered. Once certain diagnosis is achieved the treatment differs greatly.


Unfortunately herpes is not curable and will remain in your body for life. You may have future outbreaks that occur periodically, but none will likely be as severe as the initial outbreak. Treatment will involve the use of antiviral therapy and painkillers to control pain symptoms.


Syphilis is treated with simple antibiotics. These are usually administered as an injection into your buttocks. This will normally cure the infection, however a confirmatory test is advised to ensure you are clear. Specialist involvement may be required.

Genital Warts

If left untreated, genital warts will eventually disappear on their own. This however can take years to happen and due to their unsightly nature, treatment is often sought. There are a number of treatment options, all of which can take time to have an effect. These include: –

  • Cream or liquid applied to the area affected by the warts. This is usually applied a few times a week for a number of weeks. It can be painful and cause soreness.
    Surgery where a doctor or nurse cuts or lasers the wart away. This can cause scarring and the warts may still come back.
  • Freezing where a doctor or nurse applies liquid nitrogen to the wart. Again, this can cause scarring and may require a number of attempts before they are completely removed.

How to avoid catching sores on the penis?

Condoms can prevent the spread of syphilis if used during sexual intercourse. Condoms are not always effective at preventing the spread of herpes and HPV however. This is because the condom does not always cover the infected area, meaning you can still be infected in the area surrounding the penis. If you notice someone has any red sores around their genitals you should not have sex with them. This is the only way of successfully preventing the spread of herpes and genital warts.