Context

There are 3 main types of rashes in children:

• The potentially worrying: for example petechiae/purpura associated with meningococcal infections
• Named rashes: those that can be easily recognised such as chickenpox, measles, Henoch-Schonlein purpura, erythema multiforme, idiopathic thrombocytopenic purpura (ITP), eczema and psoriasis
• ‘Everything else’: nondescript viral rashes such as erythema infectiosum and roseola exanthum subitum

Children commonly present to the emergency department (ED) with a febrile illness and a rash.

Approximately 70% of such cases are attributable to viruses, such as coxsackie, echovirus or the enteroviruses. The rest result from bacterial infections such as streptococcal and staphylococcal infections, mycoplasma, rickettsial diseases, drug-related causes or Kawasaki disease.

Prodromal symptoms of such illnesses include:

• Irritability
• Loss of appetite
• Fever
• Malaise
• Headaches

Some illnesses are associated with a typical rash, which can lead to a definite diagnosis. In other cases, the clinical features may not be specific enough to enable an accurate diagnosis.