A 41-year-old woman had two months of intermittent migratory swellings in the trunk, face, and limbs associated with erythema, pruritus, and pain. The skin lesions were recurrent, typically lasting 1–2 weeks before spontaneous resolution. She denied fever, chills, or other clinical signs. She reported regular consumption of undercooked raw fish and shellfish. Physical examination showed palpable, non-pitting swelling in the right arm (Figure 1) and left leg, this leg showed subcutaneous hemorrhage (Figure 2). Laboratory analysis showed moderate eosinophilia (960 cells/mm3). The triad of eosinophilia, migratory lesions (nodular panniculitis), and raw fish consumption was highly suggestive of cutaneous gnathostomiasis.
Two weeks before arrival, she received a single dose of ivermectin (200 μg/kg) and showed no resolution. She was given albendazole (400 mg twice a day for 21 days) and showed complete and permanent resolution of the lesions. Gnathostomiasis is a food-borne zoonosis secondary to ingestion of raw fish or shellfish contaminated with larvae of Gnathostoma spp. It is observed mainly in tropical regions, and increasingly in Latin America particularly Mexico.1,2 Previous studies showed slightly more relapses in patients treated with ivermectin.3 Few clinicians outside of disease-endemic areas are familiar with gnathostomiasis. Therefore, diagnosis is often missed, which can lead to potentially serious consequences.2
Rusnak JM, Lucey DR, 1993. Clinical gnathostomiasis: case report and review of the English-language literature. Clin Infect Dis 16: 33.
Kanyarat K, Surang N, Prasert S, Wanpen C, Sutin Y, 2004. Treatment of cutaneous gnathostomiasis with ivermectin. Am J Trop Med Hyg 71: 623–628.