History
Lesions can range from asymptomatic to pruritic to extremely painful. Note the following history findings:
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Travel to areas with T penetrans, including Central America, South America, India, and tropical Africa [49]
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Walking along beach areas with bare feet or in sandals
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Pain or itching and papular or nodular eruptions, usually on the feet (although infection can occur on any area of the body to which the flea has access)
Physical Examination
Typical areas of involvement include the plantar surface of the foot, the intertriginous regions of the toes, and the periungual regions. However, other ectopic sites of infection have also been reported, including the hands, elbows, thighs, and gluteal region. [50]
Infestation in its simplest form is manifested by the appearance of a white patch with a black dot.
Lesions can also occur under the nail, potentially making diagnosis more difficult.
More advanced infestation manifests as crusted, erythematous papules; painful, pruritic nodules; crateriform lesions; and secondary infections, including lymphangitis and septicemia. A case presenting with a large bullous lesion has also been described. [51]
Tunga penetrans flea. Courtesy of Wikimedia Commons [author Philipp Weigell, https://commons.wikimedia.org/wiki/File:Tunga_penetrans_%281%29.JPG].
Image of Tungiasis infection on both feet. Courtesy of PLOS [Miller H, Ocampo J, Ayala A, Trujillo J, Feldmeier H. Very severe tungiasis in Amerindians in the Amazon lowland of Colombia: A case series. PLOS Neglected Tropical Diseases. 2019 Feb 7. Online at: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0007068.].
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A. Tangential cut through a fully developed, gravid flea embedded in the stratum corneum of the epidermis. The flea's head and thorax are enfolded in the hypertrophic anterior abdominal segments. The epidermis is hyperplastic and shows papillomatosis, parakeratosis, and hyperkeratosis.B. Tangential cut through the posterior abdominal segments of an embedded sand flea. Next to the chitinous cuticle, a microabscess has formed.C. Dead parasite; the exoskeleton of the posterior abdominal segment has remained intact; the cuticle has disintegrated at the epidermal–dermal interface. The carcass is infiltrated by neutrophils, and pus has formed.D. The head of the flea is located at the epidermal–dermal interface, has penetrated the basal membrane, and is surrounded by many erythrocytes, presumably having leaked from a blood vessel. The abdomen of the parasite is separated from host tissue by a thick, chitinous cuticle.
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A tungiasis lesion in substage 3a.
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Scanning electron micrograph of flea on day 3 after penetration. The hypertrophic zone between abdominal segments 2 and 3 is gaining a bulging shape and looks like a life-belt (x100).
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Scanning electron micrograph of flea on day 8 after penetration. The hypertrophy zone has taken the shape of a sphere. The 3 parts of abdominal segment 2 are completely bent apart. Together with the newly developed, crescent-shaped chitinous clasps, the anterior part of the flea looks like a 3-leafed clover (x32).
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Scanning electron micrograph of flea 6 hours after beginning of penetration. The penetration is almost completed; only the last abdominal segments protrude through the skin (x240).
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Scanning electron micrograph of flea in stage 2. The rear end, the genital opening, and the 4 pairs of stigmata form a miniature cone, which towers above the crater caused by pushing in abdominal segments 7 and 8 (x190).
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Life cycle of Tunga penetrans - Fortaleza stages included. Compiled and designed by Fausto Bustos and Lucas Manfield.
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Histopathologic findings in tungiasis.
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Life cycle of the chigoe flea, Tunga penetrans. Courtesy of the CDC.
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Complicated Tungiasis infection. Courtesy of Dermatology Atlas (http://www.atlasdermatologico.com.br/index.jsf) and Samuel Freire da Silva, MD.
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Tungiasis lesion under toenail. Courtesy of Dermatology Atlas (http://www.atlasdermatologico.com.br/index.jsf) and Samuel Freire da Silva, MD.
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Example of complicated infection with multiple tungiasis lesions and possible secondary infection. Courtesy of Wikimedia Commons [author R Schuster, https://commons.wikimedia.org/wiki/File:Jigger_infested_foot_(2).jpg].
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Illustration of Tunga penetrans (sand flea) in its enlarged state. Courtesy of Wikimedia Commons [https://commons.wikimedia.org/wiki/File:ChiggerBMNH.jpg].
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Removed parasite shown with needle. Courtesy of Wikimedia Commons [https://commons.wikimedia.org/wiki/File:Puce_chique_(Tonga_penetrans).jpg].
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Tunga penetrans flea. Courtesy of Wikimedia Commons [author Philipp Weigell, https://commons.wikimedia.org/wiki/File:Tunga_penetrans_%281%29.JPG].
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Image of Tungiasis infection on both feet. Courtesy of PLOS [Miller H, Ocampo J, Ayala A, Trujillo J, Feldmeier H. Very severe tungiasis in Amerindians in the Amazon lowland of Colombia: A case series. PLOS Neglected Tropical Diseases. 2019 Feb 7. Online at: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0007068.].
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Graphical abstract of predicted tungiasis occurrence within sub-Saharan Africa. Courtesy of MDPI [Deka MA. Mapping the Geographic Distribution of Tungiasis in Sub-Saharan Africa. Tropical Medicine and Infectious Disease. 2020 Jul 24;5(3):122. Online at: https://www.mdpi.com/2414-6366/5/3/122#.].
Tables
Medication Name |
Dosage/Application |
Contraindications |
Availability |
Notes |
|---|---|---|---|---|
Apply directly to the affected area once or twice daily.
If legion numbers are under 40 or legions are in clusters: Apply 3 drops of NYDA® (approximately 50 μL each) to the exposed posterior side of the flea. Repeat the procedure 3x over 10 minutes.
If fleas are in excessive hyper-keratotic skin and located on top of each other: NDYA® must be used to wet the skin intensely and repeatedly. |
No known contraindications. Shown to be safe for extended use. |
Available under the brand name NYDA®. But not available in all tungiasis endemic areas. |
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0.8% ivermectin, 0.2% metrifonate and 5% thiabendazole lotions, applied 2 consecutive days. |
No contraindications reported. |
All are readily available except for metrifonate, which is no longer commercially available. |
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Apply to all infected areas and areas at risk for tungiasis infection twice daily. |
No known contraindications. |
No longer commercially available, but made of ingredients that could be locally manufactured in areas where tungiasis is common. |
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One drop (approximately 0.05 ml) of a mixture of 20% cold-pressed virgin neem seed oil and 80% virgin coconut oil applied to the embedded flea’s abdominal tip on days 1 and 3. |
Actives in cold-pressed neem oil are not toxic following oral, inhalation, or dermal exposure. |
May be locally available where both neem trees and coconut palms grow. |
The mixture requires proper storage as azadirachtin has a high sensitivity to ultraviolet light, pH, and temperature. |
