Tungiasis: diagnosis at a glance

Abstract

A 22-year-old Japanese woman presented to our hospital with a 10-day history of pain and a rash on her right fi rst toe 10 days after a 2-week trip to Uganda, where she had stayed within Manafwa district. Although she had worn shoes and socks during student fi eldwork she reported wearing sandals with no socks around the suburban guesthouse. On examination she had a yellowish-white nodule, 5 mm diameter, with a central black spot at the rim of her right fi rst toenail (fi gure). We suspected stage 3 tungiasis and excised the nodule under local anaesthesia, during which we saw several eggs (fi gure), and also gave a tetanus toxoid booster. Stereomicroscopy showed Tunga penetrans, body length 0·5 mm, with mature eggs (fi gure). At follow-up examination 7 days later the lesion was completely healed with no signs of secondary bacterial infection. Tungiasis is an ectoparasitic skin disease caused by the female sand fl ea T penetrans, which is endemic to Central and South America, the Caribbean, and sub-Saharan Africa. The principal reservoirs of the fl ea are animals. Once inside the person, a tiny fl ea can grow up to a diameter of 10 mm within 1–3 weeks and leave hundreds of eggs. Tungiasis is an important health hazard in endemic areas, associated with long-term physical disability, immobility, and chronic pain, and self-excision can lead to life-threatening secondary bacterial superinfections such as tetanus and the transmission of blood-borne infections. Although surgical excision has been established as an eff ective treatment, another option is topical dimethicone to reduce the potential for adverse events. Tungiasis is a dynamic zoonotic disease that can be classifi ed under various stages, making diagnosis challenging as signs and symptoms change during the developmental stages of the embedded female sand fl ea. Travellers should be educated about the importance of wearing closed shoes and socks at all times during their visits to endemic areas.