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Travel-related skin diseases — larva migrans, tungiasis and myiasis
Skin diseases are among the most common reasons for consultation after travel to tropical areas; one question — where the patient was and what they did (beach, walking barefoot, bites) — together with the look of the lesion, leads to the diagnosis in most cases.
Why it matters in the exam
The exam shows a traveller back from a beach in Thailand or Brazil with a red, serpiginous, very itchy track on the foot that advances a few millimetres to centimetres a day — cutaneous larva migrans (Ancylostoma braziliense of dogs and cats). Or a white papule with a central black dot on a toe after walking barefoot on sand — tungiasis (the sand flea). Or a "boil" with a central opening in which movement is felt — furuncular myiasis from the botfly. The question tests treatment: a single dose of ivermectin 200 micrograms/kg, or 3 days of albendazole 400 mg daily in larva migrans, sterile extraction of the flea in tungiasis, and occluding the opening and removing the larva in myiasis. Remember the distinction from larva currens of Strongyloides, which advances very fast (centimetres per hour) around the buttocks and requires Strongyloides testing before steroid treatment, and the distinction from cutaneous leishmaniasis and secondary bacterial infections. In addition, a rash with fever after travel should raise suspicion of dengue, chikungunya and rickettsial infection.
Key points
- Skin diseases are among the most common reasons for consultation after travel to tropical areas, and the exposure points to the diagnosis.
- Cutaneous larva migrans presents as an itchy red serpiginous track on the foot and is treated with one dose of ivermectin 200 micrograms/kg.
- Larva currens of Strongyloides advances very fast around the buttocks and requires testing before steroid treatment.
- Tungiasis is a papule with a black dot on a toe treated by sterile extraction, and myiasis is treated by occluding the opening and removing the larva.
- A rash with fever after travel requires work-up for dengue, chikungunya, Zika and rickettsiae.
Summary table
| Disease | Exposure | Appearance | Treatment |
|---|---|---|---|
| Cutaneous larva migrans | Tropical beach, walking barefoot or sitting on sand with dog faeces | Red, serpiginous, itchy track advancing millimetres to centimetres a day, on the foot or buttocks | Ivermectin 200 micrograms/kg single dose, or albendazole 400 mg for 3 days |
| Larva currens (Strongyloides) | Tropical areas, even years earlier | Very fast urticarial track around the buttocks and thighs | Ivermectin; before steroids — test and treat |
| Tungiasis | Walking barefoot on sand in Africa and Latin America | White papule with a central black dot on the toes or under a nail | Sterile extraction, disinfection, tetanus vaccination |
| Furuncular myiasis | Fly bites in Latin America and Africa | "Boil" with a central opening, sense of movement, clear discharge | Occlude the opening (petrolatum) and remove the larva; routine antibiotics not needed |
| Rash with fever | Mosquito or tick bites | Maculopapular rash, sometimes a black spot at the bite site (eschar) | Work-up for dengue, chikungunya, Zika and rickettsiae; doxycycline for rickettsiae |
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Sources
- CDC Yellow Book — Health Information for International Travel, 2024 — Cutaneous larva migrans; tungiasis; myiasis
- IDSA clinical practice guideline on skin and soft tissue infections, 2014 — Parasitic infestations
- WHO model list and guidance on ivermectin for ectoparasites, 2023 — Dosing
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.