They usually infect the skin of the finger and toe webs, and folds under the arms, breasts, elbows, genitals and buttocks. The blisters break easily when scratched.
Broken blisters leave scratch marks and thickened skin, crisscrossed by grooves and scaling.
A mite that burrows into deep skin layers, where the female mite deposits eggs. Eggs mature into adult mites in 3 weeks. Mites are 0.1mm in diameter and can only be seen under a microscope. Scratching collects mites and eggs under the fingernails, so they spread to other parts of the body. Contact with an infested person.