Creeping eruption is also known as mobile larval rash (migrans), larval migrans, larval migrans, cutaneous wandering larval disease, wandering thread-like epidermolysis bullosa, subterranean rash, sandworm disease, and plumber’s itch rash, among many other names. It is a thread-like damage caused by larvae of hookworms, fly maggots, filarial worms, and jawworms that migrate through the skin of humans. Runner’s rash occurs in children in tropical and subtropical regions, and disseminated cases have been reported in southeastern China. The summer season is good, and the most common sites are the hands, feet and lower legs. When the eggs in the feces hatch into infective larvae, the human body, especially children, is exposed to the larvae and they burrow into the skin and develop the disease. Symptoms appear a few hours after the larvae have invaded the skin. They start as localized itching, also on the skin surface, or in striated form. The diagnosis of runner’s rash is confirmed when larvae of cat hookworm, dog hookworm, pig jaws, horse flies, horse stomach flies, etc. are found in the skin lesions. The rash of runner’s rash is characterized by red tunnel-like, sinuous lesions, and various larvae have specific rash characteristics, which may include nonspecific lesions such as erythema, papules, papules, nodules, and secondary rashes that can last for several months. About 1/3 of patients with runny rash present with transient pulmonary infiltrates and eosinophilia, and occasional hook larvae are seen in sputum. Insomnia, weight loss, and lack of energy may occur in a small number of patients. Blood eosinophils are usually increased. Transient pulmonary infiltrates may be demonstrated by lung x-ray. Pathology of runny rash: Animal larvae are not adaptable to the human body and generally do not develop to maturity in humans, staying mostly in the larval stage. Therefore, no adult worms or eggs are visible in the human body; at the same time, the larvae cannot reach their normal parasitic sites and produce ectopic lesions in the tissues and organs through which they migrate. The larvae usually reside in the granular or spiny layer of the skin, with chronic inflammatory cells and eosinophils infiltrating the skin near the tunnels, especially in the perivascular area, while the nematode larvae migrate a little deeper in the skin, but the inflammatory response is basically the same.