Tungiasis is endemic in sub-Saharan Africa, India, the Caribbean, and Central and South America. It is usually acquired while walking barefoot on sand or in shady areas near rotting vegetation. Children are at higher risk (peak age of incidence is 5-10 years), and boys are at slightly higher risk than girls. Risk factors include not wearing closed-toe footwear, poverty, and proximity to domestic or wild animal reservoirs (as fleas may exist on these animals).
Because the flea cannot jump very high, involved sites are usually limited to the feet, especially periungually. However, in small children, ectopic sites above the waist are not uncommon.
Tungiasis initially presents as red or brown macules that become nontender papules around the toenails within 24 hours of exposure. Each papule contains a flea. Within a week, the flea matures and swells to a diameter of 1 cm and may harbor up to 200 ova. The site becomes painful after 2-3 days as this engorgement occurs.
If left untreated, the site becomes very pruritic, causing the host to scratch at the lesions, which results in rupture of the flea and dissemination of eggs. The lesions then become desiccated and may leave small scars.
B88.1 – Tungiasis [sandflea infestation]
64612002 – Tunga penetrans infestation
Differential Diagnosis & Pitfalls
- Myiasis – Lesions are usually larger.
- Verruca vulgaris – Lesions are more verrucous.
- Ingrown toenail – More erythematous and indurated.
- Acute paronychia – More erythematous.
- Mycotic granulomas – More diffuse lesions.
- Melanoma – Pigment usually extends further.
- Arthropod bites – Usually lack the central punctum or black dot.
- Bartonellosis – Longer time frame.
- Squamous cell carcinoma – Longer time frame.