What would be the most appropriate treatment for a child with an annular, itchy rash and exposure to similar rashes at daycare?

The most appropriate treatment for a child presenting with an annular, itchy rash, particularly after exposure to similar rashes at daycare, is oral griseofulvin. This scenario suggests the possibility of tinea corporis, commonly known as ringworm, which is a fungal infection that can spread easily in settings like daycare. The annular shape and itching are characteristic signs of this type of fungal infection.

Oral griseofulvin is an antifungal medication specifically indicated for dermatophyte infections, including those caused by tinea species. It works by disrupting the fungal cell division and is particularly effective for infections that cover larger areas of the skin or are refractory to topical treatments. Given the context of daycare exposure, it's important to take a systemic approach to address the infection if it has spread, making oral griseofulvin the most suitable treatment in this case.

Topical hydrocortisone, antihistamines, and moisturizers are generally not effective against fungal infections and would not target the underlying cause of the rash. Topical hydrocortisone might temporarily alleviate itching and inflammation but would not treat the fungal infection itself. Antihistamines could help with itching but would not address the infection, and moisturizers are used for dry skin