What is the treatment of slapped cheek disease?

Fever control. Slapped cheek disease is also known as fifth disease. It is caused by parvovirus b19, a common virus that causes sore throat, fever, headache, and the characteristic "slapped cheek" rash. The rash usually appears towards the end of the illness and may spread to the chest and arms. The treatment is supportive care, with fever control and lots of fluids. The rash eventually goes away on its own.
None needed. Slapped cheek, also known as fifth's disease and erythema infectiosum, is a viral illness and as such there is no treatment. It is generally mild and resolves quickly on its own. If your child has a condition such as sickle cell disease, it can be more serious.