Here's the dirt on beach sand.

If your headed to the beaches (sand boxes and soil) of the Caribbean, Africa, Asia, and South America you may want to think about hook worms. It occurs from infection of larva found in sand and soil. After 1-5 days, or even over a month of larva penetrating the skin a creeping rash appears. The rash starts out as red inflamed spots and there is a creeping growing pattern of the rash as the hookworm crawls under the skin. It is associated with intense itching, burning sensation, and some swelling. Common locations include feet and buttocks, though can occur anywhere skin contacts contaminated sand or soil. It does go away on its own as the larvae die after 5-6 weeks. Anti-parastic medications can treat the infection and medications can be provided for relief of symptoms. Prevention is focused on wearing protective clothing, towels, shoes, etc.