A 76-Year-Old Woman Returning From Venezuela With Unusual Eruptions on the Feet

(See page 172 for the Photo Quiz.)

Diagnosis: Tungiasis.

This is a typical case of tungiasis, a parasitic disease caused by the sand flea Tunga penetrans. The flea favors warm, dry environments, and tungiasis is prevalent in rural Central and South America, the Caribbean and sub-Saharan Africa [1, 2]. The gravid female sand flea penetrates mammalian skin headfirst, burrowing her mouthparts into the superficial dermis to feed on the host’s blood. As its abdomen swells, the pregnant flea becomes spherical and forms unique, uniform eruptions (Figure 1 and 2). Tunga penetrans can jump vertically only about 20 cm; therefore, lesions are usually limited to the feet (see Figure 1 and 2) [3, 4]. The distinctive eruptions, limited location, and travel history can lead to the diagnosis. Some cases, however, can mimic viral warts, furuncles, abscesses, paronychia, and malignant melanomas [1]. In such cases, dermoscopy is a useful tool that enhances the visibility of subcorneal to upper dermal structures. We can easily find eggs inside the enlarged body with dermoscopy (Figure 2 arrowheads), which is a distinctive finding of tungiasis [5]. Furthermore, life activities such as breathing through spiracles (Figure 2B, arrow) and the release of feces (Figure 2C) through the openings of skin are vividly observed. In addition, the wriggling midgut fulfilled with human blood can be seen in some of the eruptions (Figure 2D and video).

Figure 1.

Clinical photographs (A) and dermoscopic image (B–D) of the patient’s feet. Arrow: dark-reddish wriggling tubular structure.

Figure 2.

(A) Typical eruptions of tungiasis. Note the white oval objects (arrowhead): released eggs. (B−D) Dermocopy enhances the visibility of subcorneal and upper dermal structures, and it shows the eggs as round white organs (B, arrowhead). Through the central dot, Tunga penetrans breathes (B, arrow) and excretes (C). Wriggling midgut filled with human blood are also seen (D).

The initial treatment is complete surgical excision of the insect [1]. If this is not possible, the entire flea should be extracted with a needle (Figure 3). Tetanus prophylaxis is recommended, especially for patients living in endemic areas [1]. Systemic antibiotics are not necessary in the majority of cases; however, antibiotics such as niridazole or oral thiabendazole should be considered when numerous and pustular lesions are present [1].

Figure 3.

Punctured flea’s body.

The wearing of closed shoes adequately prevents Tunga penetrans infection [1, 4]. Tungiasis remains an important public health problem for poor communities, and clinicians should be aware of this preventable disease.

Note

Potential conflicts of interest. All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.