The Herpes Rash
How to recognise and manage this symptom
The herpes rash is a group of blisters around the mouth or genitals
The rash is caused by white blood cell activity in the infected area
There are other STIs and non-sexually-transmitted infections that can cause a similar rash
You can your rash diagnosed online, or by your GP if you prefer
There are treatments and lifestyle recommendations available for managing your rash
What is a herpes rash?
What it looks like – a herpes rash normally looks like a collection of small, fluid-filled blisters that appear around the mouth or the genitals. When these blisters pop, they will then scab over. The herpes rash is normally accompanied by other symptoms of a herpes infection, such as:
- A burning or stinging sensation on the skin before the rash appears
- Flu-like symptoms, such as a fever, headache, tiredness, weakness, or aches and pains
- Painful urination – when the rash is in the genital area
Is it a serious problem? – getting a herpes rash is not a sign that something is seriously wrong. Almost 9 in 10 people who have the herpes virus in their body never realise it, but in people who experience symptoms the rash is one of the most common complaints that are reported. The rash also typically doesn’t last for the whole time you have an active outbreak: it takes a few days to appear and normally clears before some of the other symptoms have run its course.
When does this rash happen? – in a person who has the herpes virus in their body, the average frequency of outbreaks is four to five times per year in the first year that they have the virus. However, the virus affects people differently, so some people will have more, or fewer outbreaks. When a person is not experiencing an active outbreak, a the herpes virus stays in the body but lies dormant (doesn't do anything).
Why does herpes cause a rash?
The herpes virus infects the skin, causing the cells to start to break down. Once the virus is there, your body will start trying to fight the infection too, which itself can cause more inflammation and irritation in that area. This causes redness, blisters and itching of the skin.
The virus, and how the body responds to it can vary between people. Some people may find that they don’t get a visible rash at all, even if they have a herpes infection.
Is it a herpes rash or something else?
If you've been exposed to herpes, it could be a herpes rash – if you have had sexual contact (including vaginal, oral, or anal sex) with a person who has been diagnosed with herpes and is experiencing an active outbreak, you are likely to have become infected. You can still become infected if you used a condom as an active outbreak of herpes is very contagious.
It could also be a different STI – other sexually transmitted conditions (STIs) can also cause a rash. For example, untreated syphilis can cause a red or brown rash on the skin. Also, HIV can cause a rash in some people. It can be very difficult to tell what kind of STI a person has based on the symptoms alone as some of them can be very similar to each other.
It could also be a different, non-sexually transmitted condition – a broader range of non sexually transmitted conditions can cause a rash. The most common non-STI cause of a rash is a fungal infection of the skin. This can take on different appearances depending on what species of fungus has grown on the skin. Some are painless, some might itch, and some can even be painful.
How do you diagnose a herpes rash?
Getting an online diagnosis (and treatment) – you can use our online photo assessment service to find out whether a rash on your skin is caused by herpes. This is available at any time so you can use it at your convenience. To use our online photo assessment service, follow these simple steps:
- Take two good quality photos of the affected area of skin
- Fill in a very short questionnaire which asks a few questions about the rash
- A doctor will review your questionnaire and photos and give you a diagnosis if they can, and advise you on treatment
Can you do home testing? – If you think the rash is caused by herpes it’s possible to use a home testing kit for herpes. This is a swab test that you use on any open blisters or sores and can check for the herpes virus. However, it won’t test for other causes of rashes.
Getting diagnosed in person – you can also make a face-to-face appointment with a doctor or nurse to get a diagnosis. Go to your GP practice or nearest sexual health clinic (sometimes known as GUM clinic) to make an appointment. In your appointment, you will be asked some questions about the rash as well as more general questions about your health. They may ask detailed questions about recent sexual contacts. After this, they will examine the affected area. Then, they will come to a diagnosis and advise you on the best course of treatment. They may write a prescription which you can give to any pharmacy. If the pharmacy has your medication in store, you can have it in minutes. If not, you should be able to collect your treatment the next day.
What can you do about a herpes rash?
Getting medical treatment – herpes is treated by a family of medicines called antivirals. You can order three different types of antivirals from us. These are called Aciclovir, Valaciclovir, and Famciclovir. Antivirals can help shorten the length of an active outbreak. If you experience pain on urination when you are experiencing an active herpes outbreak, you may be able to get creams to ease this.
Managing the rash – there are some things that you can do at home to help with an outbreak:
- Wash the affected area with plain or salty water to prevent from developing infections
- Apply vaseline if you experience pain
- Avoid wearing tight clothing which may irritate the skin
- Take regular pain relief such as paracetamol. Make sure that you follow manufacturer’s guidelines. Do not take other medications which also contain paracetamol such as cold & flu tablets and drinks
- Do not share towels with others
- Avoid having oral, vaginal, or anal sex until the rash clears up
Long-term treatment for repeat rash outbreaks – if you get six or more outbreaks in a year or the outbreaks affect you severely, you may be able to take antiviral medications for up to one year to prevent outbreaks from happening, this is called suppressive therapy.
Ayoade, F. O. et al (2018). Herpes simplex. Medscape. [online] Available at: https://emedicine.medscape.com/article/218580-overview [accessed 18th July 2018].
Calabrese, L. H. et al (1987). Acute infection with the human immunodeficiency virus (HIV) associated with acute brachial neuritis and exanthematous rash. Ann Intern Med.; 107(6): 849-851. [online] Available at: https://pubmed.ncbi.nlm.nih.gov/3688679/. [accessed 13th May 2021]
Clinical Knowledge Summaries (2017). Herpes simplex - genital. NICE. [online] Available at: https://cks.nice.org.uk/herpes-simplex-genital [accessed 18th July 2018].
Dylewski, J and Duong, M. (2007). The rash of secondary syphilis. CMAJ, Jan; 176(1): 33-35. [online] Available at: https://pubmed.ncbi.nlm.nih.gov/17200385/. [accessed 13th May 2021]
Scheld, W. M., Whitley, R. J. and Marra, C. M. (2004). Infections of the central nervous system (4th ed). Pennsylvania: Lippincott Williams and Wilkins. [online] Available at: https://www.researchgate.net/publication/305161712_Infections_of_the_Central_Nervous_System_Fourth_Edition [accessed 13th May 2021]