Non-blanching rash in a child

A quick visual on the common causes of a non-blanching rash ( NBR ) in childhood. NBR is any rash in which the colour does not change with direct pressure.

A NBR can be petechiae or purpura or both. It happens due to extravasation of blood from the vasculature into the skin or mucus membranes. It does not fade with pressure. It can happen due to-physical trauma to capillaries , inflammatory injury to capillary wall , low circulating levels of platelets

Causes can be

Infective-Viral - several viral infections as◘ Enterovirus◘ Parvovirus B19◘ Dengue◘ Cytomegalovirus ( CMV )◘ Respiratory synctical virus ( RSV )◘ Epstein-Barr virus ( EBV )◘ Rotavirus◘ Adenovirus◘ Influenza rhinovirus Bacterial◘ Meningococcal◘ Scarlet fever◘ Infective endocarditis

Trauma - Accidental injury NAI e.g child abuse Increased pressure following bouts of coughing , vomiting or straining Seat belt compression in RTAs

Haematological and malignancy - Leukaemia Platelet disorders e.g Idiopathic thrombocytopenic purpura Fanconi anaemia Disseminated intravascular coagulation ( DIC ) Haemoltyic uraemic syndrome ( HUS ) Splenomegaly Neuroblastoma Neonatal alloimmune thrombocytopenia ( NAIT )

Vasculitic and Inflammatory- HSP and SLE

Others -Ehler Danlos Drug reactions Vitamin K deficiency

Idiopathic immune thrombocytopenic purpura Autoantibody mediated destruction of platelets leading to...