The sore throat started three days after a new partner and has not shifted. Tonight you tilt your head back in the bathroom mirror, and what you can see of the back of your throat looks red, perhaps with a pale spot you cannot quite make out.
Herpes can infect the throat, and the clearest way to find out is a swab taken from the sore while it is still there. At Sexual Health Clinic London that swab costs £120.63, results come within 3 working days, and we are open seven days a week at 117a Harley Street. If you would rather skip the reading, book a herpes test and walk in.
"Most sore throats after oral sex turn out to be an ordinary virus. If you can see ulcers at the back of your mouth, come in while they're there. A swab from the sore gives us a clear answer."
Dr Mohammad Bakhtiar, Clinical Lead, GMC 4694470
The thing worth knowing is that the tests differ by what is going on in the throat. Herpes leaves sores that a doctor can swab, while throat chlamydia and gonorrhoea usually cause no symptoms at all and need their own swab. Here is what each picture can mean.
Small ulcers or blisters at the back of the throat or on the tonsils
Herpes simplex virus is the family of virus behind cold sores. After oral sex it can cause a cluster of tiny blisters that break quickly into shallow, painful ulcers on the tonsils, the soft palate or the back wall of the throat. Swallowing hurts, and some people notice tender glands under the jaw.
The back of the throat is hard to inspect on your own, even with a torch and a phone camera. A doctor can look properly with a light and a tongue depressor, which is the main reason to be seen rather than to keep checking in the mirror.
A sore throat and fever after oral sex
A first herpes infection can arrive like flu, with fever, aching, a very sore throat and tender glands, and the ulcers often appear with the fever or shortly after it. Many sore throats after oral sex have another cause, and our guide to a sore throat after oral sex covers the common ones.
When a fever and a sore throat follow a new partner and ulcers are there too, that is your cue to book a swab. Treatment with an antiviral works best when it starts early in a first episode, within the first few days, so coming in while the sore is fresh helps twice: the swab is easier to read, and the doctor can discuss treatment at the same visit.
If you cannot swallow fluids, are pregnant, or have a weakened immune system, be seen the same day.
A sore throat with nothing to see
Sometimes the throat is red and painful and nobody can point to a sore. Many things cause that, and herpes is only one of them.
An antibody blood test is available for this situation, at £103.75 plus the £50 blood draw, and it is reliable from 12 weeks after the exposure. It shows whether your body has met herpes simplex virus at some point. Antibodies to HSV-1 are very common in UK adults, many of whom picked it up in childhood, so a positive result cannot show that your sore throat is herpes or that the virus is in your throat. It suits people with no sore who want to know about past exposure. If a sore appears, come back and we will swab it.
White or yellow patches
Patches on the tonsils are common with tonsillitis, with thrush and with glandular fever, which also brings a fever and swollen glands and is a frequent look-alike. Broken herpes blisters can look similar, so a doctor examines the throat and swabs any sore rather than guessing from a description. Our page on what herpes looks like shows how sores appear on other parts of the body, which helps if you have more than one place to check.
What happens at Sexual Health Clinic London
At Sexual Health Clinic London we keep this to one visit. This is how it goes.
- Walk in or book. Monday to Friday 09:00 to 18:00 and Saturday and Sunday 10:00 to 14:00, at 117a Harley Street. For a visit today, see same-day STI tests in London.
- The doctor or nurse looks at your throat with a light. They check the tonsils, palate and back wall, and ask when it started and what has changed.
- The swab is taken from the sore. A soft swab touches the ulcer for a couple of seconds. It can make you gag briefly and it is over almost at once.
- Other throat infections can be tested in the same visit. A throat swab for gonorrhoea or chlamydia is £104 per site, with results in 2 to 3 days. Added to a FAST screen, a throat swab returns in 6 hours.
- Bloods can be added if you want them. One visit can cover the herpes swab, the throat swabs and, if you wish, blood tests, and your samples reach the laboratory the same day.
- Results come within 3 working days, in one message. The consultation is optional on an individual test and included in our STI packages, so the doctor can talk you through whichever result you receive.
Swabbing works best while the sore is open. If the ulcers have already healed, a swab has nothing to find, and the antibody test above is the fallback.
Which virus it is
Our herpes swab is a PCR test, which looks for the virus's genetic material, and the laboratory reports the type: HSV-1 or HSV-2. That matters in two ways. It tells you which virus you are dealing with, and it helps the doctor explain what to expect, because HSV-1 tends to settle around the mouth and lips and HSV-2 around the genitals. HSV-1 now causes a large share of genital herpes in the UK too, so the type tells you which virus it is, not where it was caught. It also gives you something precise to say to a partner, instead of the word "herpes" alone.
If the result is positive
A doctor talks you through treatment and how to avoid passing the virus on. Herpes in the throat usually settles by itself within a couple of weeks. Recurrences in the throat are uncommon, since the virus is more likely to resurface as a cold sore on the lip. Most people are surprised by how manageable it is once someone has explained it.
Book a swab at Harley Street
At Sexual Health Clinic London our doctors see you privately, and you do not need to use your real name. Walk in on any day of the week, or book ahead if you prefer.