an incurable and sometimes fatal flu-like neurological condition that is believed to have been caused by ingestion of poorly produced L-tryptophan supplements1)
helminth infections (see below for eosinophilia in the returned traveller)
this rare chronic vasculitis can be diagnosed on basis of having 4 of the following 6 conditions with 99% specificity2)
asthma
blood eosinophilia > 10%
paranasal sinus abnormality
mononeuropathy or polyneuropathy
non fixed pulmonary infiltrates
histological evidence of extravascular eosinophils
1st and 2nd stages of allergies, sinus problems and asthma may precede stage 3 by many years
stage 3 includes multi-organ involvement such as severe nerve pain in their legs, arms and hands, renal impairment, etc.
associated with elevations of p-ANCA (whereas Wegener's granulomatosis is associated with c-ANCA)
eosinophilia in the returned traveller
incidence in returned travellers from the tropics is ~5%
it is suggestive of parasite infection such as a helminth infection although the absence of eosinophilia does not exclude helminth infection as less than half have eosinophilia
common helminth infections from the tropics
strongyloidiasis - may also cause urticarial rash around waist and buttocks
three stool examinations for ova, cysts and parasites to detect the more common gastrointestinal helminths, whose eggs may be excreted intermittently
any macroscopically visible worms (likely to be ascarids or tapeworm) should be sent for laboratory identification
specific serological testing is available for schistosomiasis, strongyloidiasis, filariasis, echinococcosis, toxocariasis and angio-strongyliasis
empirical Rx of presumed helminth infection
start Rx after stool collections
options include mebendazole, pyrantel and albendazole although of these, only albendazole is useful for strongyloidiasis, tapeworm infection or schistosomiasis.