Herpes is one of the most common causes of genital sores, and it is often confused with other conditions until it is examined properly. Our guide to private STI testing in London explains how a confidential visit works.
What are the first signs of herpes?
The first sign is often tingling, itching or a burning feeling on the skin, sometimes a day or two before anything is visible. This is caused by the virus travelling along the nerve to the skin surface. Some people also feel generally unwell, with aching or swollen glands in the groin, before any mark appears. This early stage is easy to dismiss as irritation, which is why the next stage, when small blisters form, is usually what prompts people to look more closely.
What do the blisters and sores actually look like?
The blisters are small, fluid-filled and usually appear in a cluster rather than as a single spot. They sit on a reddened base of skin and can be on the shaft or head of the penis, the vulva, the anus, the mouth or the lips. Within a day or two the blisters break open, leaving shallow, often painful ulcers. These can weep or sting, particularly when urine passes over them, before drying out and forming a crust as the skin heals underneath. The whole cycle, from first blister to healed skin, can take up to 3 to 4 weeks for a first episode.
Does a first outbreak look different from a repeat one?
Yes, a first episode is usually more extensive and more uncomfortable than any outbreak that follows. Along with the sores, a first episode can bring flu-like symptoms: fever, headache, muscle aches and tender, swollen lymph nodes in the groin. Recurrences tend to involve fewer blisters, in roughly the same area, that heal faster and with milder discomfort. Many people also notice the same tingling warning sign before each recurrence, which can prompt them to start treatment early if a doctor has prescribed it in advance.
Does herpes look the same on the penis, vulva, anus and mouth?
The pattern of tingling, blistering, ulceration and crusting is the same wherever it occurs, but the appearance is shaped by the skin at that site. On the penis, blisters and ulcers typically appear on the shaft, glans or foreskin. On the vulva, they can affect the labia and the area around the vaginal opening, and swelling can make the whole area feel sore rather than showing a single clear lesion. Around the anus, sores can be mistaken for a fissure or piles. On the mouth and lips, herpes usually shows as a cold sore, a cluster of small blisters at the edge of the lip that crusts over within a few days.
What else can look like herpes?
Several other conditions can produce marks or sores in the same area, which is exactly why a clinical examination and the right test matter more than trying to match a description online.
A short summary of what tends to be confused with herpes, and how it is told apart.
Genital warts and molluscum tend to be painless bumps rather than blisters or ulcers, folliculitis and ingrown hairs sit around hair follicles rather than forming a cluster of blisters, and thrush more often causes redness, itching and a white discharge than a defined sore. Because these can overlap in appearance, especially in early or mild cases, the reliable route is an examination rather than comparing photographs. A doctor who has seen many of these presentations can usually tell them apart on sight and confirm with the right test. Our herpes myths and facts page covers more of the common misconceptions people bring to this question.
How is herpes actually tested and confirmed?
The most accurate way to confirm herpes is a swab taken directly from an open sore or blister while it is still present, because this tests for the virus itself. A blood test looks for antibodies your immune system has made in response to past infection, which means it can show that you have been exposed to HSV-1 or HSV-2 at some point, but it cannot tell you where the infection is, when you caught it, or whether a specific sore in front of you is herpes. If you want a blood test after a possible exposure rather than because of a visible sore, it is generally more reliable from around 12 weeks after that exposure, once antibodies have had time to develop.
How testing works at our Harley Street clinic
At Sexual Health Clinic London, the herpes swab is best taken as soon as possible after a sore appears, ideally while it is still fluid-filled rather than after it has crusted over, because this is when the sample contains the most virus. The blood antibody test needs no specific preparation. Both tests are available with a walk-in appointment seven days a week at 117a Harley Street, and results are back in 2 to 3 days. If you are being screened more broadly rather than testing one symptom, the Silver package includes HSV I and II alongside chlamydia, gonorrhoea, HIV, syphilis, Mycoplasma genitalium, Ureaplasma and Gardnerella.
Book a herpes test at 117a Harley Street: PCR swab £120.63 or blood test £103.75, results in 2 to 3 days.
References
- Genital herpes, NHS
- Genital herpes, NICE Clinical Knowledge Summaries
- UK national guideline for the management of genital herpes, British Association for Sexual Health and HIV (BASHH)
- Syphilis, NHS
- Genital warts, NHS
