Sore, Ulcer, Blister or Bumps on the Penis or Private Area: What It Could Be, and When to See a Doctor
You have noticed something on your penis, foreskin, scrotum or groin — a sore that won't heal, a cluster of small blisters, white dots on the head, a pimple-like bump, red spots after sex — and the search results are either terrifying or useless. This page explains, in plain language, what the common causes look like, which ones are harmless, which ones need a test, and what to do next. It is written by Dr. Manuj Sondhi, MRCP (UK), Consultant Physician with a Fellowship in Infectious Diseases & HIV (Tata Memorial Hospital), who examines these problems every week at Nirvana Clinic, opposite Delta-1 Metro, Greater Noida.
The short version: Most bumps on the penis are harmless. A sore, ulcer or blister — especially after a new sexual contact — is different and should be examined while it is still present, because the tests that identify the cause work on fresh lesions. A painless ulcer is not reassuring; it is the one most often ignored. And if the contact was within the last 72 hours, HIV prevention (PEP) is time-critical and comes before the bump.
🔒 Private, judgment-free consultation. Your visit and records are kept between you and your doctor. · ✓ Reviewed by Dr. Manuj Sondhi, MRCP (UK), MD, DNB — Reg. No. 12-42985 · Last reviewed: October 2026
Match What You See: Common Causes by Appearance
Use this table as a guide to what is likely — not as a diagnosis. Several of these look alike, and two of the most important ones (herpes and syphilis) are regularly mistaken for each other in photographs.
| What you see | Most likely cause | Harmless or needs a doctor? |
|---|---|---|
| Cluster of small, painful, fluid-filled blisters that burst into shallow sores; may have fever, body ache, swollen groin glands; burning on urination | Genital herpes (first episode) — or a recurrence if you have had it before | See a doctor now, while blisters are fresh; swab test and antiviral treatment |
| One firm, round, painless ulcer with a clean base, 2–6 weeks after a sexual contact; heals by itself in a few weeks | Early syphilis (chancre) | See a doctor and get a blood test even if it is healing — the infection continues silently |
| Soft, ragged, very painful ulcer, often with a tender groin swelling | Chancroid or other bacterial ulcer (less common) | See a doctor — treatable with the right antibiotic |
| Flesh-coloured, soft, raised growths; single or in clusters; cauliflower-like surface; on shaft, under foreskin or around the anus; usually painless | Genital warts (HPV) | See a doctor — treatable; partner and vaccine advice; see HPV vaccine |
| Small, smooth, dome-shaped shiny bumps with a tiny dimple in the centre; several at once | Molluscum contagiosum (a viral skin infection, often sexually acquired in adults) | See a doctor — removable; not dangerous but spreads |
| Tiny white or yellowish dots on the shaft or scrotum, unchanged for years, no symptoms | Fordyce spots (normal oil glands) | Harmless — no treatment needed |
| A neat row or ring of small, uniform, skin-coloured bumps around the rim of the head of the penis | Pearly penile papules (normal anatomy, seen in roughly 1 in 5 men) | Harmless — not warts, not an infection |
| Single red, tender pimple at the base of a hair in the pubic area or on the shaft; may have a yellow head | Folliculitis or ingrown hair (common after shaving or trimming) | Usually settles; see a doctor if spreading, recurring or very painful |
| Red, shiny, itchy or sore rash on the head of the penis and under the foreskin; sometimes white curd-like material or cracks; worse in diabetics | Balanitis (often fungal), or irritation from soaps or condoms | See a doctor — simple treatment, but recurrent balanitis is a reason to check blood sugar |
| Intensely itchy small bumps, worse at night, also on wrists, between fingers or waistline; partner itching too | Scabies | See a doctor — treatable; whole household and partner need treating together |
| A cut, tear or raw area, often on the underside of the head or the frenulum, appearing right after sex; stings with urine | Friction injury or frenulum tear | Usually heals in 1–2 weeks with rest from sex; see a doctor if it keeps reopening, bleeds or becomes an ulcer |
| Slow-growing lump, thickening, non-healing sore or red velvety patch on the head or foreskin, especially over 50 or with a tight foreskin | Needs to rule out penile cancer (rare, but curable when found early) | See a doctor without delay |
Bump or Sore After Sex: Why the Timing Matters
If the lesion appeared after a sexual contact, when it appeared is one of the most useful clues you can give the doctor:
Same day to 2 days
Almost always friction, a small tear, or an allergic reaction to a condom or lubricant. Infections do not produce sores this fast.
2 to 12 days
The usual window for a first herpes outbreak, often with flu-like symptoms. Chancroid also appears in this range.
3 to 6 weeks
The classic timing for a syphilis chancre — single, painless, easy to ignore. Warts and molluscum can appear anywhere from weeks to months later.
Was the contact within the last 72 hours?
Then the bump is the second priority. HIV post-exposure prophylaxis works only if started within 72 hours of the exposure — the earlier the better. Read about PEP or call the clinic today; the skin problem can be examined at the same visit. If a condom broke, the same applies.
What Happens at the Consultation
- A short, private conversation. When you noticed it, whether it hurts or itches, any recent sexual contacts, other symptoms, and whether you have diabetes or any condition affecting immunity. Nothing you say is judged; the aim is only to narrow down the cause.
- Examination. A brief look at the area, including under the foreskin and the groin glands. This alone identifies most harmless bumps immediately, and you leave reassured.
- Targeted testing where needed. A swab from a fresh blister or ulcer (PCR), a syphilis blood test, an HIV test at the correct interval, and urine or swab testing for gonorrhoea and chlamydia if there is also discharge or burning. Not everyone needs every test — see the full list of STI tests and treatment.
- Treatment the same day. Bacterial causes are cured with the correct antibiotic course; herpes is controlled with antiviral treatment; warts and molluscum have specific treatments; fungal balanitis responds quickly to the right antifungal. Partner advice and prevention (condoms, vaccination, PrEP where HIV risk is ongoing) complete the visit.
Please don't do these
Don’t buy antibiotics or antiviral tablets from a chemist on a guess — a wrong antibiotic can partially treat syphilis, make the sore disappear and leave the infection active. Don’t apply steroid creams, Dettol, toothpaste or “skin-whitening” creams to the area. Don’t try to cut, burn or pull off a wart at home. Don’t rely on “sexologist” clinics or online sellers promising a guaranteed cure or permanent treatment — no such promise is medically honest, and the delay costs you the window when testing is most accurate.
When It Is Urgent
Seek same-day medical care if you have
- A sore with high fever, severe pain, or rapidly spreading redness and swelling of the penis or scrotum
- Inability to pass urine, or a foreskin that is stuck retracted and swollen (paraphimosis)
- A painful, hot, tender swelling of a testicle
- Severe headache, stiff neck or confusion along with genital blisters
- Any genital lesion if you are living with HIV, on chemotherapy or steroids, or have poorly controlled diabetes
For a medical emergency go to the nearest hospital emergency department. For urgent concerns outside clinic hours, book an online consultation with Dr. Manuj for 8 AM the next morning.
Examined and Treated by Dr. Manuj Sondhi
MRCP (UK), MD, DNB · Consultant Physician & Diabetologist · Fellowship in Infectious Diseases & HIV, Tata Memorial Hospital
Dr. Manuj Sondhi is a Visiting Consultant in Infectious Diseases at Fortis Hospital, Greater Noida, and sees genital skin problems, herpes, syphilis, gonorrhoea, chlamydia, warts and HIV prevention as routine, judgment-free work at Nirvana Clinic. Because he also treats diabetes, recurrent balanitis and fungal infections are assessed with blood sugar in mind, not just a cream. Read his full profile or see the HIV, STI & sexual health clinic page.
📍 GF-93, Ground Floor, Sun Twilight Complex, opposite Delta-1 Metro Station, Greater Noida 201308 · In-clinic & online consultations · Serving Greater Noida, Noida Extension, Pari Chowk, Knowledge Park and Delhi NCR
Frequently Asked Questions
Is a bump or sore on the penis always an STD?
No. Many bumps on the penis are harmless and have nothing to do with sex — pearly penile papules, Fordyce spots, pimples, ingrown hairs and small cysts are all common. However, a sore or ulcer, a cluster of blisters, or new fleshy growths after a sexual contact can be an infection that needs treatment. A quick examination settles the question far more reliably than searching images online.
I have small white dots on the head of my penis. Are they normal?
Very often yes. Small white or yellowish dots on the head or shaft, present for years and unchanged, are usually Fordyce spots (tiny oil glands) or pearly penile papules (a neat ring of bumps around the rim of the head). Both are normal, not infections, and need no treatment. They are not warts. If the spots are new, growing, itchy or appeared after a new partner, get them checked.
What does a painless sore on the penis mean?
A single, firm, painless ulcer that appears a few weeks after a sexual contact is the classic early sign of syphilis, and it heals on its own even without treatment — which is exactly why people ignore it. The infection then continues silently. Any painless ulcer on the penis, foreskin or scrotum should be seen by a doctor and tested with a blood test, even if it is already healing.
What causes painful blisters or sores on the penis?
A cluster of small painful blisters that burst into shallow sores, sometimes with fever, body ache and swollen groin glands, is most often genital herpes. Painful sores can also come from friction injury during sex, a torn frenulum, fungal infection under the foreskin, or less common infections. Early examination while the sores are fresh allows the right test and treatment to be started the same day.
I noticed a pimple on my private part. Can I pop it?
Please don't. A pimple-like bump in the pubic area or on the shaft is usually folliculitis or an ingrown hair, and squeezing can drive infection deeper or leave a scar. Keep the area clean and dry, avoid shaving over it, and if it is enlarging, very painful, has a yellow head that keeps returning, or there is more than one, let a doctor look at it.
Can I just send a photo instead of coming to the clinic?
A photo can help with triage, but a reliable diagnosis of a genital sore needs examination, sometimes with a swab or blood test. Several conditions look alike in pictures — herpes and syphilis in particular — and the treatments are completely different. For a first-time sore, an in-clinic visit is recommended; follow-ups and recurrences can usually be handled online.
How long should I wait before seeing a doctor about a bump?
If there is a sore, ulcer or blisters, come as soon as possible — ideally while the lesion is still present, because tests work best on fresh lesions. For a painless bump with no other symptoms, it is reasonable to watch for one to two weeks; if it persists, grows, multiplies or bleeds, book a consultation. If you had an unprotected contact within the last 72 hours, call the same day about HIV prevention regardless of the bump.
Is the consultation confidential?
Yes. Sexual health consultations at Nirvana Clinic are private and judgment-free, and your records stay between you and your doctor. Genital skin problems are routine medical work here, seen every week, for men of every background including MSM. In-clinic consultation is near Delta-1 Metro, Greater Noida; online consultation is available for follow-up.
Stop Comparing Photos. Get It Looked At.
One confidential visit near Delta-1 Metro: examination, the right test if needed, treatment started the same day — or simple reassurance that it is nothing. Online follow-up available.
Related reading: Genital Herpes Treatment · STD / STI Testing & Treatment · Confidential HIV Test · PEP After HIV Exposure · Sexual Health Clinic