Final answer:
A nurse should advise the parent of a child with diaper dermatitis to apply topical hydrocortisone cream to reduce inflammation and relieve itching, although it doesn't treat the underlying cause of the rash.
Step-by-step explanation:
A nurse is providing teaching to the parent of an infant who has diaper dermatitis. The nurse should instruct the parent to apply a topical corticosteroid cream, such as hydrocortisone, to the affected area. Hydrocortisone cream is helpful in reducing inflammation and relieving minor skin irritations, itching, and rashes. It works by reducing the secretion of histamine, which in turn suppresses the immune system's inflammatory response, hence limiting inflammation and symptoms such as pruritus (itching) and rashes. However, while hydrocortisone is effective in managing symptoms, it does not treat the underlying cause of the rash.