What is the most likely condition for a child with a red, raised serpiginous-shaped rash and severe itch, who has played barefoot in the yard?

The presence of a red, raised serpiginous-shaped rash accompanied by severe itching is highly indicative of larva migrans. This condition typically occurs due to the migration of larvae from soil or sand, commonly following contact with contaminated areas, such as yards or beaches. The serpiginous appearance of the rash is characteristic, as it reflects the path the larvae take as they move beneath the skin.

In this scenario, since the child has played barefoot in the yard, it raises the likelihood of exposure to the causative agents, which are often found in the feces of animals, such as dogs or cats. The intense itching is also a common symptomatic feature of larva migrans, as the body reacts to the larvae's presence.

While other conditions might present with rashes or itching, they do not align as closely with the specific characteristics and context provided. For instance, erythema migrans is usually associated with Lyme disease and has a different presentation. Tinea pedis is a fungal infection and typically presents with scaling and flaking, rather than a serpiginous pattern. Insect bites could cause a rash and itch but are unlikely to create the distinct serpiginous shape described in this case. Thus, larva migrans stands out