Test your diagnostic skills in our regular dermatology quiz. What is this rash of sudden onset in a young child who is afebrile and happy?
A 6-month-old boy presents to the hospital accident and emergency department with sudden onset of a rash on his trunk and arms (Figure 1). He has had a viral respiratory tract infection for two days. His two older siblings are well.
On examination the boy has multiple swellings with nonblanching overlying purpuric discolouration. His hands and feet are swollen. There are no mucosal lesions and he is afebrile and happy.