You are in: eMedicine Specialties > Dermatology > PARASITIC INFECTIONS TungiasisArticle Last Updated: Feb 1, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Neil F Gibbs, MD, Assistant Clinical Professor, Departments of Pediatrics and Medicine, University of California, San Diego School of Medicine; Assistant Chair, Program Director, Pediatric Dermatologist, Department of Dermatology, Naval Medical Center, San Diego Neil F Gibbs is a member of the following medical societies: American Academy of Dermatology, Association of Military Dermatologists, and Society for Pediatric Dermatology Editors: Abdul-Ghani Kibbi, MD, Chairman and Professor, Department of Dermatology, American University of Beirut Medical Center, Lebanon; Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University School of Medicine; Consulting Staff, Mountain View Dermatology, PA; Lester F Libow, MD, Dermatopathologist, South Texas Dermatopathology Laboratory; Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System Author and Editor Disclosure Synonyms and related keywords: chigoe flea, jigger, pigue, nigua, pico, bicho de pie, bug of the foot, Tunga penetrans, T penetrans INTRODUCTIONSection 2 of 10
  BackgroundTungiasis is an infestation by the burrowing flea Tunga penetrans or related species. The flea has many common names, including chigoe flea, jigger, pigue, nigua, pico, and bicho de pie (bug of the foot). Tungiasis was first reported in crewmen who sailed with Christopher Columbus. The flea is indigenous to the West Indies/Caribbean region, but it has spread to Africa, India, Pakistan, and Latin America. Travelers to endemic areas may import cases to other countries, including the United States. These painful infections can cause significant morbidity in groups, such as soldiers. To reproduce, the flea requires a warm-blooded host. In addition to humans, reservoir hosts include cattle, sheep, horses, mules, rats, mice, dogs, pigs, and other wild animals. PathophysiologyThe main habitat is warm, dry soil and sand of beaches, stables, and stock farms. Upon contact, the fleas invade unprotected skin. The most common site of involvement is the feet (interdigital skin and subungual area). The flea has limited jumping ability. Both the male and the nonfertilized female flea feed intermittently on warm-blooded hosts. Once impregnated, however, the female flea anchors herself to the skin by using biting mouthparts and burrows into the epidermis. Because the process is painless, a keratolytic enzyme may be involved. The flea expands, often reaching 1 cm in diameter. The head is down into the upper dermis feeding from blood vessels, while the caudal tip of the abdomen is at the skin surface, often forming a punctum or an ulceration. The flea breathes through this opening. In many cases, this is described as a white patch with a black dot. Over 1-2 weeks, more than 100 eggs, which fall to the ground, are individually released from this exposed orifice. Afterwards, the flea dies and is slowly sloughed by the host. The eggs hatch on the ground in 3-4 days, go through larval and pupal stages and become adults in 2-3 weeks. The complete life cycle lasts approximately 1 month. FrequencyUnited StatesImported cases rarely occur in the United States. Fourteen cases were reported as of 1989. InternationalIn the endemic areas, the prevalence ranges from 15-40%, but cases in other areas are sporadic. Six percent of the patients visiting a travel-associated dermatosis clinic in Paris had tungiasis. Mortality/MorbidityIndividual lesions may be painful, although sometimes they are pruritic or even asymptomatic. In most cases, tungiasis resolves without complications. However, heavy infestations may lead to severe inflammation, ulceration, and fibrosis. The risk of secondary infection is high. Lymphangitis, gangrene, and ainhum may occur. Death from tetanus associated with tungiasis has been reported. CLINICALSection 3 of 10
HistoryLesions can range from asymptomatic to pruritic to extremely painful. PhysicalThe typical presentation is a nodule (usually on the foot) that slowly enlarges over a few weeks in a patient who has recently been in an endemic area. The nodule can range from 4-10 mm in diameter. CausesTungiasis is caused by an infestation with the burrowing flea T penetrans. DIFFERENTIALSSection 4 of 10
Insect Bites
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| Drug Name | Niridazole (Ambilhar) |
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| Description | Not available in United States. Has been reported to be completely effective in lysing imbedded fleas in children who are infected. Response was quicker when a second dose was given 1 wk after the first dose. Combination of direct toxic action on flea and anti-inflammatory action on surrounding tissue was postulated. |
| Adult Dose | 30 mg/kg PO in juice |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity; known G-6-P deficiency |
| Interactions | May elevate theophylline serum levels increasing toxicity (monitor serum levels and reduce dose prn) |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | May cause nausea, vomiting, and abdominal pain |
| Media file 1: Histopathologic findings in tungiasis. | |
 | View Full Size Image | Media type: Photo |
Article Last Updated: Feb 1, 2007
