Petechial Rashes

Broad approach to causes of petechia / purpura: 

Vascular (rash that does not blanch with pressure) 

• Infection (meningococcal and gram –ve sepsis)
  
• Accidental or non-accidental trauma
  
• Henoch Schonlein Purpura

Thrombocytopenia 

• ITP
  
• Hypersplenism
  
• Consumption
  
• Decreased production (includes bone marrow infiltrates such as leukaemias)
  
• Immune and autoimmune

Platelet dysfunction 

• Drugs
  
• Metabolic and inherited 

Coagulopathy 

• Inherited
  
• Acquired