What skin disease does the sailor’s curse, “I’ll be jiggered” refer to?

It refers to parasitization by the jigger (Tunga penetrans). The gravid female flea burrows into the skin to where the eggs mature, and she passes them through an opening in the skin to the environment, where they mature in the soil. This flea is found in sandy shaded soil, and early sailors frequently took refuge in these areas, where they acquired this noxious pest. In most cases, only one or two jiggers are present, but some individuals have had hundreds of lesions at the same time. This parasitic disorder was first described by the Spanish conquerors and sailors of the Santa Maria that shipwrecked on the coast of Haiti at the end of the 15th century.