Non-blanching rash in children
Author – Dr Charlotte Wilson Editor – Dr James Mackintosh
Last updated 29/10/24
Table of Contents
Introduction
Non-blanching rashes in children can be a cause of worry and panic! This is understandable as sometimes this can be a sign of a serious underlying cause. Often people, and worried parents, associate non-blanching with meningococcal sepsis. However, there are other causes which are more common and less concerning.
Having a structured approach to taking the history of a child presenting with a non-blanching rash will help ensure you cover all the important information and work through the differentials to initiate a safe management plan for the patient.
So what do we mean by non-blanching rash? ‘Non-blanching’ means that the rash does not disappear when pressure is applied. Some people may be familiar with the glass test too- which is where the rash does not disappear when viewed through glass against the skin.
Non-blanching rashes are most commonly petechiae (<2mm) or purpura (>2mm). These are caused by bleeding under the skin. The rash may be widespread or localised to a particular area.
Presenting Complaint
You can still use the SOCRATES acronym to guide your gathering of information when assessing a rash
Site
Where is the rash?
Which areas of the body does it affect?
A rash caused by Henoch Schonlein Purpura (HSP) for example usually covers legs and buttock areas.
A more widespread rash may be viral exanthem or more serious and suggest meningococcal sepsis, especially if rapidly spreading, often due to extensive thrombocytopenia.
A circumferential rash that may raise suspicion of non-accidental injury (NAI) include strap marks or grab marks around wrists or neck area, which are unusual areas for accidental trauma. May appear as linear bruises or abrasions which may raise suspicion of NAI. Bruises in non-bony areas such as face, ears and neck should always raise suspicion of non-accidental injury.
Onset
When did the rash start?
Did it start suddenly or did it gradually start appearing?
Some rashes which have a more sudden onset include meningococcal sepsis, and would be associated with fever and neck stiffness. Immune Thrombocytopenia (ITP) and HSP often present with sudden rashes which spread too.
Non-blanching rashes which have a more gradual and insidious onset include those associated with acute leukaemia and Haemolytic Uraemic Syndrome (HUS) often has a slower onset of symptoms.
Character
What does the rash look like?
Petechiae vs purpura? (petechiae <2mm or purpura >2mm)
How does it feel?
Palpable purpura is often associated with vasculitis, particularly HSP but can also be a feature of meningococcal sepsis.
ITP is typically non-palpable.
Radiation
Is the rash spreading anywhere else?
An rapidly evolving or spreading rash is consistent with meningococcal sepsis and viral exanthem.
Associated symptoms
Any ulceration of the lesions?
Any bleeding?
Itch?
Any respiratory symptoms?
Had any recent cough/cold symptoms?
Fever?
Lethargy?
Weight loss?
N&V?
Diarrhoea?
Meningism- neck stiffness or photophobia?
It is important to ask about these symptoms, as a preceding viral illness if often associated with HSP and ITP, so can help you narrow down your differentials
A presentation with abdominal pain with diarrhoea and vomiting makes a diagnosis of HUS more likely.
If the rash is bleeding and itchy, this may suggest a type of allergic reaction where the child has caused trauma to the area by scratching.
Fever, lethargy and weight loss and systemic symptoms which can often suggest a serious underlying cause such as acute leukaemia, and is an important differential to consider if the child has presented with a non-blanching rash and chronic signs and symptoms.
Neck stiffness, fever and rash raises suspicion for meningitis or meningococcal sepsis, and should raise alarm bells in your head that this child is acutely unwell and should be discussed urgently with a senior.
Timing
Has the rash changed since you first noticed it?
Is it rapidly spreading?
A rapidly spreading non-blanching rash may make you more suspicious of meningococcal sepsis, as the bacterial which typically causes this called neisseria meningitidis releases toxins in the bloodstream and causes damage to the blood vessels, leading to the rash like appearance as blood leaks into the skin.
Exacerbating and relieving factors
Have you tried anything that has helped the rash/made it worse?
For example a rash related to an allergy may improve with antihistamine treatment and using topical treatments
The use of NSAIDs usually make rashes in HSP, ITP and HUS worse and increase risk of bruising and bleeding.
A non blanching rash in meningococcal sepsis will only improve with prompt treatment including IV antibiotics and supportive care e.g. hydration.
Severity
May not be very relevant to rash history unless the patient is experiencing any pain with the rash.
Red Flags
It is important to demonstrate to the examiner that you are aware of some of the serious causes of a non-blanching rash and ask about red flag features to screen for them.
Symptoms that suggest meningococcal sepsis include fever, neck stiffness, photophobia, lethargy, and headaches. The child will look unwell and likely be scoring on the PEWS chart, and have abnormal signs such as increased HR, temperature, irritability in infants and even reduced conscious level.
Acute Lymphoblastic Leukaemia (ALL) is another serious cause of a non-blanching rash. This is a type of blood cancer and is the most common type of cancer in children. ALL results in low platelets and low red blood cells and so the child will often present with a history of breathlessness or fatigue, pale complexion, easy bruising (due to low platelet count) as well as fever or history of recurrent infections. The symptoms can often be vague and so it is important to keep this differential in mind.
Make sure you always keep safeguarding and non-accidental injury in the back of your mind as a potential differential with this presentation. Features that could suggest NAI or raise concerns about safeguarding include delayed presentation to GP/hospital, an inconsistent history from parents and carers about when the rash started and when it was first noticed, as well as changes in the child or parents behaviour.
Other features which should raise concerns include bruising in areas not commonly injured in accidental trauma such as behind the ears, back, thighs, upper arms. Remember that non-ambulant children are unlikely to have bruises.
If you have any concerns about the child’s wellbeing or safeguarding concerns, you should communicate this to a senior and discuss with your paediatric safeguarding lead, who will be able to advise on how to manage the situation appropriately.
You should specifically ask about these red flag signs and symptoms, to cover serious causes of non-blanching rashes.
- Spreading rash/petechiae or purpura
- Persistent fever
- Child appears lethargic, pale, floppy i.e. septic child
- Prolonged CRT >2sec
- Hypotensive (usually a late sign of shock in children)
- Easy bruising
- Bulging fontanelle in neonate
- Any signs of meningitis (including photophobia, neck stiffness, headache)
- Any change in consciousness/ reduced GCS (may present with irritability, uncontrollable crying, confusion, aggressive behaviour in a child, this is why it is always helpful to ask the parents/carers if this behaviour is normal for the child)
MLA Tip 💡
Make sure to escalate to a senior early if a child is showing any worrying signs or you are unsure, it is better to be safe and seek support early.
Differentials
| Differential | Features |
|---|---|
Meningococcal sepsis | Fever, neck stiffness, photophobia, headache, irritability and high pitched cries in infants, signs of shock. The child will look unwell. |
Henoch-Schonlein purpura (HSP) | Rash is usually distributed over legs and buttocks, palpable purpuric rash. Often have abdominal and joint pain. May have renal involvement (haematuria, proteinuria). |
Idiopathic thrombocytopenia (ITP) | Multiple petechiae lesions, often over sites of minor trauma, usually non palpable, child otherwise well, other bleeding symptoms such as recurrent epistaxis, haematuria or bleeding gums. Preceding viral illness common. |
Haemolytic uraemic syndrome (HUS) | Abdominal pain, diarrhoea that becomes bloody, Reduced urine output or anuria. Usually preceded by gastroenteritis illness with diarrhoea, may be preceded by contact with farm animals. |
Viral illness | Petechiae from coughing, vomiting will be above nipple line area on chest. The child may have had coryza, cough, fever but no red flag features. |
Acute leukaemia | Anaemia, pallor, fatigue, night sweats and weight loss. May have lymphadenopathy or hepatosplenomegaly. |
Trauma | Clear history of trauma in common site for accidental injury. Plausible and consistent explanation. |
Non-accidental injury | Lesions in unusual distribution or uncommon site for injury. Delayed presentation. Patterned injuries e.g. handprint mark. |
Background
In any paediatric history you will ask about past medical history including birth history (prenatal, perinatal and postnatal), medications and immunisation status, allergies, social history including development, and family history. Here are some extra things to ask about which demonstrate your knowledge about the causes of non-blanching rashes in children:
Past Medical History – ever had a rash like this before? Any preceding viral illness/ diarrhoea (as we discussed above often associated with ITP and HSP, also to note HUS usually preceded by gastroenteritis)
Family History – any FH of any clotting disorders? Most common hereditary bleeding disorders include haemophilia A, haemophilia B, and von Willebrand disease.
While coagulopathy is a very rare cause of a non-blanching rash in a child, it is important to show you have considered this and can rule it out as a differential.
Examination
When examining the patient, you should keep your differentials in mind and look for signs that confirm or refute your potential diagnosis. Children presenting with a non-blanching rash will usually have blood tests including an FBC, blood film and CRP with further investigations as indicated by their presenting features.
- Fifteen-minute consultation: the child with a non-blanching rash, BMJ https://ep.bmj.com/content/103/5/236
Management of the child with a Non-blanching rash (NBR), https://www.clinicalguidelines.scot.nhs.uk/nhsggc-guidelines/nhsggc-guidelines/emergency-medicine/management-of-the-child-with-a-non-blanching-rash-nbr-ie-petechiae-purpura-ecchymoses/
Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management, https://www.nice.org.uk/guidance/ng240
- BSAC, https://bsac.org.uk/paediatricpathways/petechial-purpuric-rash.php