crust and the flea's carcass is removed by host repair mechanisms and the skin begins to heal. With the flea gone, inflammation may still persist for a while. Although patients would not present within the 5th stage of tungiasis as the flea would be dead and no longer in the body, this stage is characterized by the reorganization of the skin (1–4 weeks) and a circular residue of 5–10 mm in diameter around the site in penetration. An intraepithelial abscess, which developed due to the presence of the flea, will drain and later heal. Although these disease residues would persist for a few months, tungiasis is no longer present. In severe cases, ulcers are common, as well as complete tissue and nail deformation. A patient may be unable to walk due to severe pain if too many of the lesions are present in the feet. Suppuration (pus formation), tissue death, auto-amputation of digits (via ainhum), and chronic lymphedema may also be seen. If the patient is not vaccinated, tetanus is often a complication due to secondary infection. Necrosis and gangrene are other common complications of severe infestation and superinfection. Staphylococcus aureus and Wolbachia endobacteria can be transmitted by the chigoe flea, as well as nearly 150 other different pathogens. For these reasons, the chigoe flea should be removed as soon as possible. Incubation Because of the relatively rapid onset of tungiasis, the incubation period tends to be short. Although some reddening around the site of penetration occurs, the first symptoms are perceived in stage 2 as itching and severe pain, usually a day after penetration. Cause Tungiasis is strictly caused by chigoe fleas (the term transmission does not apply because Tunga penetrans is itself responsible for the disease.) The preponderance of tungiasis lesions on the toes may be because chigoe flea is a poor jumper, attaining only a high of 20 cm. But the reality is more complex; for example, the jumping ability cannot explain why hands are the second-most affected body part. Lesions on the hands are better explained by playing in the sand and noting that hands are often used to remove sand from other parts of the body. The occurrence of tungiasis lesions on the toes, between them, and on the soles can be easily explained because most of the victims are poor, walk barefoot, and live in places where the sand (home to chigoe fleas) constitutes