Management of the Child with a Non-Blanching Rash (NBR): (i.e. Petechiae, Purpura & Ecchymoses)

Management of the Child with a Non-Blanching Rash Algorithm go straight to algorithm if patient unwell.

It is not uncommon for children to present to the Emergency Department with a non-blanching rash (accounting for approx. 2% of all attendances) +/- fever and other systemic features of illness. ^{1, 2}

The minority of children with invasive bacterial infections, such as meningococcal disease (MCD), must be distinguished from the majority of individuals presenting with a non-blanching rash secondary to a benign self-limiting illness (90% of paediatric hospital presentations with NBR  do not have MCD; furthermore petechiae can be found in up to 3% of well infants). ^{3, 4, 5}

Meningococcal disease remains the leading infectious cause of death amongst the paediatric population within both the UK and the developed world. The highest rates of invasive infection are in children < 5yrs (particularly those under 1yr of age); a second peak occurs amongst 11 – 22yr olds. Early recognition & treatment has been shown to improve outcome. ^{6, 7}

• Petechiae: pinpoint-sized capillary haemorrhages (< 2mm in diameter)
• Purpura: essentially coalesced petechiae measuring > 2mm
• Ecchymoses: lesions of a similar appearance to purpura, but > 1cm in size (i.e. bruises) ⁸

Differential Diagnoses:

1. Invasive Meningococcal Disease
2. Sepsis with other Bacteria
3. Trauma / Non-Accidental Injury
4. Thrombocytopenia
5. Viral Illness
6. Mechanical (secondary to transient increases in vascular pressure e.g. straining, coughing or vomiting; manifestation of petechiae in the distribution of the superior vena cava – i.e. above the patient’s nipple line)
   
   
7. The following groups are distinct diagnoses and often have specific signs and symptoms:
   1. ITP: Idiopathic Thrombocytopenia
   2. HSP: Henoch-Schönlein Purpura
   3. Acute Leukaemia
   4. HUS: Haemolytic Uraemic Syndrome ^{5, 8, 9}

Management of the Child with a Non-Blanching Rash: ^{6, 7, 15, 16}

Idiopathic Thrombocytopenia: 

Click to view larger version of image

• Most common haematological cause of a non-blanching rash
• Affected children are typically well (with an absence of fever / other signs of infection)
• Majority present between the ages of 2 – 5yrs
• 60% have a preceding viral infection                     
• Petechiae, purpura and bruising are often present in sites of frequent mild trauma
• Physical examination is usually otherwise unremarkable (i.e. no hepatosplenomegaly)
• Caused by destruction of circulating platelets by IgG-based platelet antibodies
• The platelet level at which petechiae appear spontaneously is usually ≤20 x 10⁹/L
• Suspicion of ITP always necessitates taking a FBC + Blood Film (demonstrating isolated thrombocytopenia with an otherwise normal blood film appearance)
• A self-limiting disorder overall; > 80% spontaneously resolve within 6 – 8 weeks ^{8, 10}

Henoch-Schönlein Purpura:

Click to view larger version of image

• An IgA-mediated systemic small vessel vasculitis
• Classical symmetrical distribution of palpable purpura - predominantly over the child’s buttocks, lower limbs and ankles
• Often associated with arthritis, peripheral oedema and colicky abdominal pain
• May have associated renal involvement (with haematuria +/- proteinuria)
• Diagnosis is uncommon < 2yrs of age; usually manifests between 3 – 10yrs
• Incidence peaks throughout the winter months; often preceded by an URTI
• Take blood for: FBC (platelet levels should be within normal range), Coagulation Screen, U&Es and Bone Profile (to monitor renal profile)
• Blood Pressure measurement (determine BP centile based on child’s sex, age + height)
• Urinalysis; plus send urine samples to quantify protein : creatinine ratio and for microscopy, culture & sensitivity
• Most cases have a benign course with remission occurring within ~ 6 weeks ^{8, 10, 11}

See RHC Clinical Guidelines for further information regarding initial assessment and management

Acute Leukaemia:

• Most common paediatric malignancy → accounts for 1/3^rd of all childhood cancers
• Typically short history (manifesting over days-to-weeks)
• Consider in children with: hepatosplenomegaly, lymphadenopathy, easy bruising, petechiae (in absence of trauma), pallor, fatigue, weight loss, bone + / - joint pain etc.
• Diagnostic tests: Baseline Bloods (including: FBC, Blood Film, U&Es, Bone Profile, LFTs, LDH); CXR (to exclude mediastinal mass)
• Discuss any suspected new diagnoses with on-call consultant haematologist ^{9, 10}

Haemolytic Uraemic Syndrome:  

• Rarely causes petechiae or purpura
• Commonest cause of acute renal failure in Scotland
• Usually follows a diarrhoeal prodrome (often bloody)
• Most cases due to verotoxin-producing Escherchiae coli
  (0157:H7 most prevalent subtype)       
• A triad of:
  1. Microangiopathic Haemolytic Anaemia
  2. Thrombocytopenia                                                                  
  3. Acute Renal Failure
• Mainstay of management involves acute assessment of patient’s intravascular status with subsequent fluid resuscitation as appropriate
• Correction of electrolyte abnormalities thereafter
• Avoidance of NSAIDS e.g. Ibuprofen
• See link to HUS guideline below for preliminary tests and further management ^{10, 12}

See RHC Clinical Guidelines for additional information

Further Considerations:

Viral Cause:

• Petechial rash may be associated with viral illnesses (of which, enterovirus & adenovirus are the most prevalent causes)
• Presentation is often with an URTI +/ - ‘flu-like symptoms or gastroenteritis
• In a study of 69 children with a petechial rash in Germany: Schneider et al. (2013) found that petechial rashes restricted to an SVC distribution + a CRP value within normal parameters (quantified as < 6mg/L) did not have Invasive Meningococcal Disease ^{5, 8, 9, 13}

Trauma:  

Where there are concerns that a NBR may be due to non-accidental injury:

• Address safeguarding concerns & discuss with Senior Medic / Consultant
• See existing Child Protection Guideline for further details regarding appropriate management: ^{4, 5, 8, 14}