What infection preceded this rash?

Salmon-pink scaly papules are seen on boy's trunk and extremities
rash

A mother brings her eight-year-old boy to the paediatrician by his mother over concerns of a new-onset rash. 

He is otherwise healthy, though his mother mentions that he was unwell two weeks prior to the rash appearing. 

On examination, numerous small salmon-pink scaly papules are seen on his trunk and extremities.