Tungiasis

Synonyms

Several popular designations:

Europe: Sandfloh.

Mexico, Caribbean islands, Peru: chigoe flea, jigger flea, pico, chique, piroque, nigua Argentina: pique.

Brazil: bicho dos pe´s, pulga de porco, pulga da areia.

Sudan: moukardan (Sudan).

South America: puce chique, ogri eye, kuti, suthi-pique, sikka, chica, and piqui.

Epidemiology

Ocurring preferentially in poor communities, beaches and farms in the Caribbean, South America and sub-Saharan Africa.

Prevalence rates in humans 21% to 83%.

Definition

Ectoparasitosis by the the female sand flea Tunga penetrans.

Aetiology & Pathogenesis

Transmission is through the bite of an infected flea, or by direct contact with an infected animal. The female sand flea Tunga penetrans (or less common Tunga Trimamillata) burrows into the skin, enlarges fromm 1 mm up to 1 cm, and expells several hundred eggs within 2-3 weeks.

Signs & Symptoms

Mostly on the nail rim: itchy, and painful lesions due to fissuing, hindering from normally walking; foreign body-sensation. Superinfection leads to formation of pustules, suppuration and ulcers. Expelled eggs and the release of brownish threads of faeces are pathognomonic signs.

Localisation

Preferentially but not exclusively on feet, toes, under the toenails, and interdigital sites.

Classification

None.

Laboratory & other workups

Tetanus immune status.

Dermatopathology

Not needed. Presence of the parasite, eggs or chitinous fragments of the female flea in the dermis, bearing hundreds of eggs within its body. Accompanying polymorphous round cell infiltrate.

Course

Self limiting.

Complications

Loss of toenails, deformation and auto-amputation of digits. Risk of superinfection (staphylococci and streptococci) and tetanus in unvaccinated patients.

Diagnosis

Travel history and clinical feature in typical localization. Identification of Tunga penetrans.

Differential diagnosis

Subungual warts; pyogenic granuloma, foreign bodies, acute paronychia, cutaneous larva migrans, cysts, dracontiasis, arthropod bites, melanoma.

Prevention & Therapy

Prevention: Closed shoes and socks and avoidance of secondary infection.

Selflimited infestation. Death of the fleas after 3 weeks.

Surgical extraction of the flea (sterile conditions) and treatment of secondary infection.

Ivermectin single dose (200 μg/kg body weight).

Special