Petechiae and Purpura

https://www.rch.org.au/clinicalguide/guideline_index/fever_and_petechiae_purpura/

Key Points

• Majority of Cases: Most children presenting with petechiae do not have a serious bacterial infection or meningococcal disease, and a specific cause often remains unidentified.
• Urgent Management: Children with petechiae/purpura who are seriously unwell require immediate medical attention.

Background Information

• Serious Bacterial Infections: Non-blanching rashes, with or without fever, may be associated with conditions like meningococcal disease.
• Impact of Vaccination: Routine immunisation has significantly reduced the incidence of pneumococcal and meningococcal bacteraemia.
• Differential Diagnoses: There are numerous infective and non-infective causes for petechiae and purpura (detailed below).

Definitions

• Petechiae: Pinpoint non-blanching spots.
• Purpura: Larger non-blanching spots (>2 mm).
• Blanching vs Non-Blanching Rashes: Unlike other common rashes (e.g., viral exanthems, urticaria), petechiae and purpura do not blanch with pressure. This can be tested using the ‘glass test’—applying a firm transparent object against the rash to assess if it disappears.

Clinical Assessment

• Immediate Review: Any child presenting with fever and petechiae/purpura should be evaluated promptly by a senior clinician.

History Taking

• Immunisation Status: Note incomplete or under-6-month-old infants.
• Symptom Onset: Rapid onset and progression of symptoms or rash.
• Medications: Previous antibiotic use may obscure signs of bacterial infection.
• Risk Groups: Consider immunosuppressed children and those with a history of invasive bacterial infections.
• Trauma History: Assess any history of trauma or injury.
• Associated Symptoms: Bleeding tendencies, abdominal pain, joint pain, difficulty mobilising.
• Other Factors: Travel history and exposure to sick contacts.

Examination Criteria

• Signs of Serious Illness: Unwell children often present with:
  • Vital Sign Abnormalities: Tachycardia, tachypnoea, or oxygen desaturation.
  • Shock Symptoms:
    • Cold Shock: Narrow pulse pressure, cold extremities, prolonged capillary refill.
    • Warm Shock: Wide pulse pressure, bounding pulses, flushed skin, rapid capillary refill.
  • Altered Conscious State: Irritability, inconsolable crying, lethargy.
  • Musculoskeletal Symptoms: Limb tenderness or difficulty mobilising.
• Further Consideration: Haematological causes, hepatomegaly/splenomegaly, lymphadenopathy, and joint swelling or erythema.

Differential Diagnoses

Causes of petechiae and/or purpura

Viral	Enterovirus Adenovirus Influenza
Bacterial	Neisseria meningitidis  (meningococcal disease) Streptococcus pneumoniae Haemophilus influenzae Group A streptococcus Staphylococcus aureus
Mechanical	Vomiting or coughing – occurs in the distribution of the superior vena cava which is above the level of the nipples Local physical pressure eg holding child during procedure, tight tourniquet Non-accidental injury or accidental injury
Haematological	Immune thrombocytopenia (ITP) Malignancy including acute leukaemia Aplastic anaemia Disseminated intravascular coagulation (DIC) Haemolytic uraemic syndrome (HUS)
Other	Henoch-Schönlein purpura (HSP) Vasculitis Drug-induced thrombocytopenia

Note: There are additional causes of petechiae that should be considered in newborns (eg congenital cytomegalovirus, toxoplasmosis, neonatal lupus). Any newborn with petechiae should be promptly reviewed with a senior clinician

Management Considerations

• Immediate Interventions:
  • Antibiotic Administration: Use age-appropriate dosing and avoid certain medications in neonates as outlined.
• Consultation and Escalation:
  • Specialist Input: Consult with local paediatric teams for assessment and potential escalation of care.
  • Transfer: Arrange for transfer if care exceeds the facility’s capabilities.
• Discharge Consideration:
  • Low Risk Assessment: Discharge may be considered if a serious cause of petechiae/purpura is deemed unlikely after thorough clinical evaluation, with clear advice for parents to return if symptoms worsen.