Interleukin (IL)-18 cascade-mediated mechanism is deeply involved in host defense against parasitic infections both in vivo and in vitro. A patient who acquired hookworm-related cutaneous larva migrans (HrCLM) in Pattaya, Thailand, was investigated for the transition of serum Th2 cytokines.

A 5-year-old healthy girl had walked barefoot on a beach in Pattaya, Thailand. After returning to Japan, linear red nodules appeared on her foot plantar and dorsum. Although the parasite remained undetected in a surgery, she was administered oral ivermectin twice at 1-week interval. Her eosinophil count, immunoglobulin (Ig) E level, and serum immune-related Th2 cytokine levels (IL-3, IL-4, IL-5, IL-13, IL-18, and IL-33) were sequentially measured.

The IL-18 cascade was found to be largely involved in HrCLM. IL-18 and IL-13 exerted an anthelmintic action along with increased eosinophil counts.