Purpuric and petechial rashes in adults and children: initial assessment

Bleeding into the skin or mucosa from small vessels produces a purpuric rash, or smaller petechiae (1-2 mm in diameter). Purpura is not a diagnosis but can be the presenting feature of serious conditions, such as meningococcal sepsis and acute leukaemia, which require urgent diagnosis and management. Equally, it can cause patients alarm but requires little more than a single assessment and reassurance. Differentiating between the two scenarios is important. This article focuses on recognition of the serious diagnoses and recommendations for urgent referral. Once such diagnoses have been excluded, other causes can be investigated or the patient managed by observation alone.