Petechial, Purpuric Rash

Overview

At least 90% of children with fever and petechiae will NOT have meningococcal disease. However, recognition and early treatment of the child with meningococcal disease is paramount. All children with fever and petechiae should be reviewed by a registrar or consultant. If invasive meningococcal disease is suspected, administer parenteral antibiotics immediately, but do not delay hospital admission.

Remember A cardinal sign of a purpuric rash is that it does not blanch on pressure, unlike exanthema, telangiectases, or allergic rashes.

Definitions
Petechiae: Pinpoint non-blanching spots.
Purpura: Larger non-blanching spots (>2mm)

Remember The majority of children with fever and petechiae do not have a cause identified – they are presumably due to viral infections.

Approach

History
- Age
  - Neonates and infants – congenital bleeding disorders, acquired thromboyctopaenia, possible child abuse
  - Children – Above diagnosis + immune thrombocytopaenia purpura, viral infection, Henoch-Schonlein pupura, milder congenital bleeding disorders
- Time course
- Distribution of purpura
- Drug history
Examination
- General
- Skin examination
- Lymph nodes
- Hepatomegaly
- Splenomegaly
Investigations
- FBC
- Peripheral blood smear
- Prothrombin time (PT) and INR
- Activated partial thromboplastin time (APTT)

Differential Diagnosis based on Platelet Count

Purpuric rash + Normal thrombocyte levels (Thrombocytopenic purpuric syndromes)

Henoch Schonlein pupura
Cutaneous small vessel vasculitis
- Kawasaki disease
- Leukocytoclastic vasculitis
Hand, foot and mouth disease (Coxsackie virus)
Papular-purpuric gloves and socks syndrome (PPGSS)
Atypical measles
Meningococcemia
Rickettsial diseases
Gianotti–Crosti syndrome
Vitamin D deficiency