The child with a non-blanching rash: how likely is meningococcal disease?

To examine a number of simple clinical features and investigations in children with a non-blanching rash to see which predict meningococcal infection.

A total of 233 infants and children up to 15 years of age presenting with a non-blanching rash were studied over a period of 12 months. Clinical features and laboratory investigations were recorded at presentation. The ability of each to predict meningococcal infection was examined.

Eleven per cent had proven meningococcal infection. Children with meningococcal infection were more likely to be ill, pyrexial (>38.5 degrees C), have purpura, and a capillary refill time of more than two seconds than non-meningococcal children. Five children with meningococcal disease had an axillary temperature below 37.5 degrees C. No child with a rash confined to the distribution of the superior vena cava had meningococcal infection. Investigations were less helpful, although children with meningococcal infection were more likely to have an abnormal neutrophil count and a prolonged international normalised ratio. No child with a C reactive protein of less than 6 mg/l had meningococcal infection.

Most children with meningococcal infection are ill, have a purpuric rash, a fever, and delayed capillary refill. They should be admitted to hospital and treated without delay. Children with a non-blanching rash confined to the distribution of the superior vena cava are very unlikely to have meningococcal infection. Measurement of C reactive protein may be helpful-no child with a normal value had meningococcal infection. Lack of fever at the time of assessment does not exclude meningococcal disease.