A 40-year-old Male with a Serpiginous Foot Rash

This case has been inspired by events in the Torres Straits and details have been changed to ensure patient anonymity.

History

A 40-year-old male presented to his primary health care practice during the wet season somewhere in the Torres during the wet season. He had an intensely itchy rash to his right ankle for the past five days. It started out as a small but painful raised erythematous lesion then began to migrate around his ankle. The rash was found nowhere else on his body. He didn’t have a fever, abdominal pain, diarrhoea or cough. He had recently been doing some gardening barefoot around a flooded creek and described the water to be quite muddy and contaminated. He is an otherwise well male with no past medial history, regular medications or allergies.

Clinical Findings

What are your differential diagnosis?

How would you approach this patient?

The Case Continued…

A clinical diagnosis of cutaneous larva migrans was made by the discerning rural generalist. The patient was treated with Ivermectin and topical corticosteroids (to ease the intense itch). He was encouraged to wear shoes next time he was gardening!

Pearls from the Torres

Cutaneous larva migrans is an itchy skin infestation caused by animal hookworm larvae (e.g infected dogs and cats). The larvae (found in contaminated animal faeces) penetrate directly through the skin.  They can’t complete their lifecycle in the human host and so meander under the skin for the rest of their days! Individuals infected with hookworm larvae develop a itchy papular rash at both the site of penetration and overlying the snake-like tracts as the larvae move under the skin. Other diagnoses to consider in this case could include scabies, impetigo and allergic contact dermatitis.

Hookworms are a common parasite found in northern parts of Australia and tropical countries. They are treated with oral anthelmintics (e.g. ivermectin, albendazole) and antihistamines and topical corticosteroids help with the itch! Prevention (like most things!) is key: wear shoes and lie on a towel when at a beach frequented by dogs!

Further Reading

Cutaneous larva migrans