Rash
Rashes are very common and are not usually serious. But occasionally they can be a sign of leukaemia or other types of blood cancer. Find out when to get a rash checked out.
Summary
- Rashes are extremely common. Often, they clear up on their own.
- But rarely, a rash can be a symptom of leukaemia or another type of blood cancer.
- If you have a rash that does not fade when you press on it, or a rash that is spreading very quickly, call 999 or go to A&E straight away.
- If you have a rash that lasts longer than a week or is painful, visit NHS 111 online, call 111 or make an appointment with your GP.
About rashes
Rashes are extremely common. Most of the time they’re not serious. Often, they clear up on their own within a few days.
But, rarely, a rash could be a sign of leukaemia and other types of blood cancer, especially if you also have other symptoms of blood cancer.
Like all symptoms of leukaemia, a rash can be caused by many things. Having a rash does not mean you definitely have leukaemia. But if you’re worried about your symptoms, it’s a good idea to see your GP.
Why do people with blood cancer get a rash?
There are a few reasons that someone with blood cancer might get a rash.
Low platelets
- If you have blood cancer, cancer cells can fill up your bone marrow and stop it making enough healthy blood cells. This includes platelets, which usually help your blood clot.
- If you do not have enough healthy platelets, you might get bleeding from tiny blood vessels in your skin. This causes a rash.
- It looks like tiny pinpricks underneath your skin. They do not fade when you press on them or roll a glass over them.
- On white skin, this type of rash may look red, purple or brown.
- On black or brown skin, it might look dark brown or purple, but it can be harder to see.
Leukaemia cells in your skin
- Sometimes, leukaemia cells can build up in your skin. This is called leukaemia cutis.
- It is very rare. It is not usually the first symptom of leukaemia.
- It can cause a few different types of rash. These could be:
- Small spots
- Larger, bruise-like patches
- Small lumps
- Larger lumps
- Raised scaly patches
Infections
- Blood cancer can also lower your white blood cell count, which makes it harder for your body to fight infections. Some infections cause a rash.
Some treatments for blood cancer can cause a rash as a side effect. We have separate information about treatments for people who already have a diagnosis.
What might a leukaemia rash look like?
The most common type of rash in people with leukaemia is a pinprick rash. Here are some examples. Other conditions can also cause rashes that look like this.
Photos of pinprick rashes
Pinprick rash on a leg
Pinprick rash on a back
Rashes due to leukaemia cells in your skin (leukaemia cutis) are very rare. They can look quite variable. Here are some examples. Other conditions can also cause rashes that look like this.
What else can cause a rash?
Rashes can be caused by lots of things. Most people who have a rash do not have blood cancer.
Other things that can cause a rash include:
- Hot weather
- Clothing that rubs or chafes
- Skin conditions like eczema or psoriasis
- Infections
- Insect bites
- Allergies
- Some medicines
- Some autoimmune conditions
- Other types of cancer
When to seek help
Call 999 or go to A&E straight away if you have:
- A rash that does not fade when you roll a glass over it
- A rash that appeared very suddenly or is spreading very quickly
If you have a rash that lasts longer than a week or is painful, visit NHS 111 online, call 111 or make an appointment with your GP.
Nearly 4 in 10 people with leukaemia wait 3 months or more before contacting a GP about their symptoms.
Some signs that you should contact your GP include a rash that:
- Looks like pinpricks or bruises under your skin. It might look red, purple or brown. It can be harder to see on black or brown skin.
- Is all over your body.
- Is painful.
- Is accompanied by a fever or other symptoms of leukaemia.
If you have a pinprick rash and your doctor can’t identify a cause, they should consider an urgent blood test. If they don’t offer you a blood test, ask for one.
If you are struggling to get help
Nearly 3 in 10 people with leukaemia have to speak to their GP three or more times before getting a diagnosis.
There may be many possible explanations for your symptoms for a GP to consider.
If you have to go back to your GP three or more times about the same symptom, remind them about Jess’ rule. This encourages GPs to ‘reflect, review and rethink’, particularly if:
- You still have the symptoms
- They have got worse
- They are unexplained
Take a look at our Spot Leukaemia campaign to find out what we’re doing to help the public and GPs spot the signs of leukaemia sooner.
Sources
We used an AI tool to help identify relevant evidence sources for this webpage, such as scientific journals and clinical guidelines. A human checked the reliability of these sources.
Sources we used to develop this information
Black GB, Boswell L, Harris J, Whitaker KL. What causes delays in diagnosing blood cancers? A rapid review of the evidence. Primary Health Care Research & Development. 2023 Jan;24:e26. DOI: https://doi.org/10.1017/S1463423623000129
Clarke RT, Jones CH, Mitchell CD, Thompson MJ. ‘Shouting from the roof tops’: a qualitative study of how children with leukaemia are diagnosed in primary care. BMJ Open. 2014 Feb;4(2):e004640. DOI: https://doi.org/10.1136/bmjopen-2013-004640
Clarke RT, Van den Bruel A, Bankhead C, Mitchell CD, Phillips B, Thompson MJ. Clinical presentation of childhood leukaemia: a systematic review and meta-analysis. Archives of Disease in Childhood. 2016 Oct 1;101(10):894-901. DOI: https://doi.org/10.1136/archdischild-2016-311251
Criado PR, Criado RF, Ianhez M, Miot HA. Chronic pruritus: a narrative review. Anais Brasileiros de Dermatologia. 2025 Aug 18;100(3):202409008. DOI: https://doi.org/10.1016/j.abd.2024.09.008
Ely JW, Stone MS. The generalized rash: part I. Differential diagnosis. American Family Physician. 2010 Mar 15;81(6):726-34. Available at: https://www.aafp.org/afp/2010/0315/p726 [Accessed Augusst 2026]
Howell DA, Smith AG, Jack A, Patmore R, Macleod U, Mironska E, Roman E. Time-to-diagnosis and symptoms of myeloma, lymphomas and leukaemias: a report from the Haematological Malignancy Research Network. BMC Blood Disorders. 2013 Oct 31;13(1):9. DOI https://doi.org/10.1186/2052-1839-13-9
National Institute for Health and Care Excellence (NICE). Clinical Knowledge Summary: Haematological cancers - recognition and referral. Revised 2025. Available at: https://cks.nice.org.uk/topics/haematological-cancers-recognition-referral/ [Accessed May 2026]
National Institute for Health and Care Excellence (NICE). Suspected cancer: recognition and referral. NICE guideline NG12. 23 June 2015; updated 25 April 2026. Available at: https://www.nice.org.uk/guidance/ng12 [Accessed May 2026]
NHS cancer programme: faster diagnosis framework. November 2022. Available at: https://www.england.nhs.uk/publication/cancer-programme-faster-diagnosis-framework/ [Accessed May 2026]
NHS England. National Cancer Patient Experience Survey 2024. Available at: https://www.ncpes.co.uk/latest-national-results/ [Accessed May 2026]
NHS Scotland. Scottish referral guidelines (SRGs) for suspected cancer: Haematological cancers. Available at: https://www.rightdecisions.scot.nhs.uk/scottish-referral-guidelines-srgs-for-suspected-cancer/haematological-cancers/ [Accessed May 2026]
PDQ Supportive and Palliative Care Editorial Board. Pruritus (PDQ®): Health Professional Version. 2025 Jan 17. In: PDQ Cancer Information Summaries [Internet]. Bethesda (MD): National Cancer Institute (US); 2002-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK65789/ [Accessed August 2026]
Rolston KV. Infections in patients with acute leukemia. In: Infections in Hematology 2014 Oct 20 (pp. 3-23). Berlin, Heidelberg: Springer Berlin Heidelberg. DOI: https://doi.org/10.1007/978-3-662-44000-1_1
Yook HJ, Son JH, Kim YH, Han JH, Lee JH, Park YM, Chung NG, Kim HJ, Bang CH. Leukaemia cutis: clinical features and outcomes of 56 patients. Acta Dermato-Venereologica. 2022 Feb 11;102:1123. DOI: https://doi.org/10.2340/actadv.v102.1123
Need support?
You are not alone. We're here for you whether you have a diagnosis yourself or know someone who has. If you'd like advice, support, or a listening ear, call our freephone helpline on 08088 010 444 or send a WhatsApp message to 07500 068 065.
Help us improve our information
We aim to provide information that’s reliable, up-to-date, and covers what matters to you. Please complete our short survey to help us improve our information and make sure it meets your needs.
About our information
This information is aimed at people in the UK. We do our best to make sure it is accurate and up to date but it should not replace advice from your health professional. Find out more about our information.
Page last reviewed: 10 September 2026
Updated September 2026
Next review due: 30 September 2029
Related content
Spot Leukaemia
Spot Leukaemia is an awareness campaign created by Leukaemia Care to raise awareness of the …
What is leukaemia?
Leukaemia is a type of blood cancer. It starts when cells in your bone marrow …
Just diagnosed with leukaemia
It can be hard to know where to start and what to do after a …
Advocacy support
Free advocacy support for people affected by leukaemia. Get help with work, healthcare, treatment decisions, …
Tests and diagnosis
Leukaemia is usually diagnosed using blood tests and bone marrow tests. You might also need …
Types of leukaemia and related blood cancers
There are many types of leukaemia, myeloproliferative neoplasms and myelodysplastic syndromes. Find out about the …
Need help understanding this information?
Our support team is here to answer your questions and provide guidance.
Contact Support