Gnathostomiasis, an emerging imported disease^1-3 characterized by recurrent episodes of migratory swellings and creeping eruptions (cutaneous larva migrans)^4-7 as well as extracutaneous involvement including pulmonary, gastrointestinal, genitourinary, CNS,^8-10 and ocular^11,12 is typically accompanied by pronounced eosinophilia, inflammatory lesions and a history of disease, travel to or residence in an endemic area.^1-3 A history of subcutaneous lumps that come and go spontaneously^1,4 even in the absence of cutaneous larval migrans⁶ suggests the diagnosis; evaluation of returning travelers with subcutaneous swelling was reviewed.¹³ Calabar swelling of Loa loa infection can mimic gnathostomiasis. Gnathostomiasis is endemic in Mexico.^4,14,15

In SE Asia, CNS eosinophilia usually reflects an infection with Angiostrongylus cantonensis, Gnathostoma spinigerum or Cysticercosis cellulosae.¹⁶ Sensitivity, specificity, positive predictive value and negative predictive values are reportedly 100% for EIA and IB detection of serum antibodies to G. spinigerum using low molecular weight components of partially purified somatic and ES antigens.¹⁷ Detection of antigen is reliable for diagnosis using an extract from the adult G. doloresi worm.¹⁸ DNA-based testing is not yet available for diagnosis of myeloencephalitis probably caused by G. spinigerum.¹⁹ The current treatment of gnathostomiasis involves administering albendazole sulphoxide which leads to the outward migration of the 3^rd stage larva.²⁰ Serologic testing for gnathostomiasis is performed in the Department of Helminthology of the Faculty of Tropical Medicine at Mahidol University in Bangkok, Thailand.¹ Production of monoclonal antibodies against G. nipponicum promises improved serodiagnosis.²¹