A young boy with fever and red rash all over the body

A child presented with a one week history of a painless non-pruritic erythematous rash. The rash initially appeared on his back, chest, and abdomen before it became widespread. Two days after the appearance of the rash, he developed fever with a maximum temperature of 39°C, accompanied by progression of the rash with coalescence over the trunk and limbs. In a local hospital, he was given three days of oral cefixime to treat a suspected respiratory infection. His fever persisted, with a temperature of 38-39°C, mainly at night. In addition, the rash on his limbs worsened, he coughed white sticky sputum, and had a mild sore throat. On examination, the rash was red, maculopapular, and blanching. It was densely distributed on the boy’s chest and abdomen (fig 1), back (fig 2), and lower limbs (fig 3). His tonsils were red and his tongue was bright red with prominent, white tipped papillae (fig 4).

Laboratory tests showed a normal white cell count (8.89×10⁹/L, reference range 4-10×10⁹/L), an increased C …