Penile sores can be caused by irritation, allergies, inflammation or infections, including STIs. Lesions that persist, increase, spread or present other symptoms require medical evaluation.
Among the possible causes of penile sores are friction during sexual intercourse, irritation from products or fabrics, allergies, inflammation and sexually transmitted infections (STIs).
Below, understand which characteristics deserve attention, when a penile sore may be related to an STI and how the urologist investigates the cause.
How to identify penile sores that may need medical evaluation
Can a penile sore be an STI?
Yes. Some STIs can cause sores, blisters or ulcers on the penis. However, not every genital sore is related to a sexually transmitted infection.
Medical assessment considers the characteristics of the lesion, sexual history and other symptoms. When necessary, laboratory tests help confirm the diagnosis.
Genital herpes
The genital herpes is caused by the herpes simplex virus (HSV). It can cause small painful blisters that evolve into penile sores, as well as itching, burning and pain when urinating.
Transmission occurs mainly through sexual contact with infected skin, mucous membranes or lesions. Some people, however, may not show symptoms.
Syphilis
The syphilis is an STI caused by the bacterium Treponema pallidum. In the initial stage, a single penile sore may appear, usually painless, at the site where the bacterium entered.
Transmission occurs mainly through sexual contact with infected lesions or mucous membranes.
Diagnosis may involve blood tests, such as treponemal and non-treponemal tests. Medical assessment determines which tests are necessary in each case.
Other STIs
Other infections can also cause genital lesions, such as chancroid, lymphogranuloma venereum and some manifestations of HPV.
As different conditions can present similar symptoms, the World Health Organization recommends clinical assessment and, when available, laboratory investigation in cases of anogenital ulcers.
Can penile sores be caused by sexual intercourse?
Yes. Friction during sexual intercourse can cause irritation, small fissures or penile sores.
Prolonged sexual activity or activity with increased friction can promote these penile sores, especially when there is little lubrication. Using a condom and lubricant can help reduce friction.
On the other hand, wounds or blisters after sexual intercourse can also be related to STIs. Therefore, it is not possible to determine the cause of penile sores solely from the timing of when the lesion appeared.
When should penile sores not be treated at home?
It is not recommended to treat a penile sore on your own without identifying its cause.
The use of antibiotics, antifungals, or corticosteroid ointments without medical guidance can mask symptoms, hinder diagnosis and, in some cases, worsen the penile sore.
Also avoid applying alcohol, hydrogen peroxide, or other irritating substances. Do not pop blisters, remove scabs, or manipulate the penile sore.
If the penile sore persists or is accompanied by other symptoms, seek medical care to identify the cause and determine appropriate treatment.
How does a doctor investigate penile sores?
Clinical evaluation
The diagnosis begins with analysis of the history and characteristics of the penile sore.
| Situation | What it may indicate |
|---|---|
| The lesion appears rarely | It may be related to irritation, friction, or another isolated factor, but the cause of the penile sore cannot be determined based solely on frequency |
| The lesion appears frequently or recurs | Requires medical evaluation, especially when the penile sore becomes recurrent |
| The lesion occurs in different situations | It may justify investigation to identify triggering factors or a persistent condition |
| There is pain, blisters, discharge, fever, or other symptoms | Clinical evaluation may be necessary and, when indicated, laboratory investigation |
| There is risky sexual exposure or possibility of an STI | The healthcare professional may consider tests and other evaluations according to the history and characteristics of the penile sore |
When might tests be necessary?
Some genital ulcers, including penile sores, require laboratory investigation.
According to the CDC, unusual lesions or those that do not respond to initial treatment may also require further investigation, including biopsy in selected situations.
| Examination or assessment | When might it be considered? |
|---|---|
| Test for syphilis | When there is clinical suspicion or a history of exposure. |
| Test for herpes | When the lesion, such as a penile sore, has features consistent with genital herpes. |
| Test for HIV | According to exposure history and medical assessment. |
| Tests for other STIs | Based on symptoms, lesion characteristics (including penile sores), and possible exposures. |
| Laboratory tests | When needed to complement the investigation. |
| Biopsy | It may be considered for persistent, recurrent, or atypical lesions, such as persistent penile sores, especially when the diagnosis remains uncertain. |
Can penile sores disappear on their own?
Yes. Some irritations and minor injuries can improve spontaneously.
However, the disappearance of the lesion does not necessarily rule out an STI or another condition that requires treatment.
Penile sores that persist, recur, or change should be evaluated to identify the cause.
How to prevent penile sores?
Some precautions can reduce the risk of irritations, trauma, and STIs:
- maintain good penile hygiene;
- avoid products that cause irritation;
- use condoms during sexual activity;
- use lubricant to reduce friction;
- get tested for STIs when indicated;
- keep HPV and hepatitis B vaccination up to date, according to health recommendations;
- avoid sharing objects that may cause injury.
The CDC also recommends strategies for STI prevention, including vaccination and safer sexual practices.
