Skin rash, and when
it is urgent
A skin rash is a symptom and not a condition. The causes run from harmless to urgent, and a diagnosis belongs with your GP.
On this page are the signs that mean you call today, and the common kinds of rash with what can be done about them.
Six signs that mean
you call today.
- Fever, chills or you feel yourself getting more ill quickly
- The rash clearly spreads within hours
- Swelling of lips, tongue or throat, or trouble breathing or swallowing
- Drowsiness, confusion, neck pain or sharp headache in bright light
- Blisters or skin peeling away, or spots in your mouth or eyes
- A rash in a baby, or in someone with a weakened immune system
If you recognise any of this, calling is the only right answer. How the rash looks no longer counts then.
- During office hours
- Your own GP
- Evening, night or weekend
- The out-of-hours GP service
- Someone looks ill and waiting does not feel right
- 112
How a rash behaves
Not what you see but what it does says the most. This is also the first question you get, from us and from your GP.
Gone within hours
Welts that come up and disappear within a day, sometimes returning elsewhere. That pattern fits hives, and then what came before it counts.
The same for weeks
Patches that stay put and change slowly. That points more to something with the skin barrier than to a reaction of the moment.
Exactly where something touched
A sharp border following the shape of a strap, a piece of jewellery or a collar. The shape gives the cause away, and it is usually contact.
Outward from one spot
Started at one point and spread from there. That course belongs to a different group of causes than something that came up everywhere at once.
Four that are common.
These four are the most common. They help you describe what you see, and that makes the conversation with your GP shorter.
Contact reaction
A defined spot with a clear shape, exactly where something touched your skin. Starts hours to days afterwards.
Where to go
Your GP, who can request allergy tests if needed.
Eczema
Itching comes first, dry flaking patches that keep coming back in the same place.
Where to go
Your GP. There is treatment for it and it starts there.
To the eczema pageHives
Raised, itchy welts that move around and are gone again within a day, to return elsewhere.
Where to go
Your GP. With swelling of lips or throat: call the emergency number.
A virus
A rash together with fever or feeling ill, often fairly sudden and spread over the body.
Where to go
Your GP, and urgently if someone looks ill with it.
What helps and what we advise against
Ointment on an unexplained rash changes the picture the doctor has to assess.
This works
- Watching how ill someone feels. That counts for more than how the rash looks, and it decides whether you call today or tomorrow.
- Taking a photo at the start. A rash changes quickly and the doctor rarely sees the first day.
- Writing down when it started and what came before it: a new product, a new medicine, something eaten, somewhere you walked.
- When in doubt, contact your GP or the out-of-hours service. They can judge how quickly you need to be seen.
- Cooling for itching, and otherwise leaving it alone until you know what it is.
We advise against this
- Putting ointment or cream on an unexplained rash before a doctor has looked. You change the picture with it.
- Waiting with fever, rapid spread or spots that do not fade under pressure.
- Searching the internet for a photo that looks like it. A rash looks different on everyone, and that is why a doctor looks.
- Booking a cosmetic treatment while there is an unexplained rash.
- Scratching, however hard that is. Scratching makes the picture less clear and the skin more vulnerable.
Frequently asked questions
Can I tell from the rash whether it is serious?
Not reliably. A rash that looks harmless can still be serious, and on darker skin the difference is hard to see anyway. How ill someone feels counts for more: fever, drowsiness, neck pain or breathlessness are reasons to call at once.
My rash itches badly but otherwise I feel fine.
Then there is usually no hurry, and it is still a question for your GP. With swelling of lips, tongue or throat, or with breathlessness, that does not apply and you call at once.
Could it come from a new product?
It could, especially if the spot has the shape of where the product was. Stop using it, keep the packaging and take it to your appointment.
Why is there no list of photos here?
Because you would go looking for the photo that looks most like you, and that is exactly the wrong way round. A rash looks different on everyone, and on darker skin often very different from the photos you find online.
Can I come to you for this?
With an unexplained rash your GP makes the diagnosis first. Once you know what it is, you can come to us for the repair of your skin barrier, in consultation with your doctor.
To your GP.
If in doubt, today.
With an unexplained rash a doctor should make the diagnosis. Once you know what it is, we can work on your skin barrier alongside that, in consultation with your doctor.
Book a consultation once you know what it is
With an unexplained rash a doctor makes the diagnosis first. After that we look at what can be done for your skin barrier. If you do not know yet, do call; then you hear whether it belongs with us or not.
Book a consultationNot sure yet? Ask your question