linguatula serrata , entitled tongue worm , and a worm - like blood sucking parasite ; belongs to the phylum pentastomida . this zoonotic pentastomid parasite live mainly in the nasal passages and frontal sinuses of carnivorous , principally of dog and occasionally other animals including reptiles , birds and mammals ( 1 ) . the eggs , containing embryos are expelled either with nasal secretions or in the feces . when ingested by an intermediate host such as rodents ( rabbits and rats ) , ruminants ( sheep , goats , cattle and camels ) and accidentally by humans ( 1 ) , the embryos migrate to the mesenteric lymph nodes and various other organs , where they feed on blood and fluids and molt to become mature nymphal stage . the nymph may retain alive in the intermediate host for at least two to three years , where they become encapsulated ( 2 ) . humans are accidentally infected by ingesting water and vegetables or frequently by eating raw liver containing nymphs ( 2 ) . to cause infection the nymphs must cling to the mucus membrane of the mouth before being swallowed or when vomited . in human beings they may produce no symptoms , but sometimes cause severe catarrh , bleeding and suppuration and may cause much sneezing , difficulty in breathing , irritations and discomfort of upper respiratory tract , when they obstruct the nasal passages ( 1 , 2 ) . in iran , high prevalence of l. serrata infestations ( range ; 16.1% - 76.5% ) in dogs , sheep , goats , cattle and camels from shiraz ( 3 ) , shahre - kord ( 4 , 5 ) , kerman ( 6 - 9 ) , tabriz ( 10 ) , rafsanjan ( 11 ) , nagaf - abad ( 12 ) and isfahan ( 13 ) have already been reported . sporadic infestation of human linguatulosis have been documented from different provinces of iran including tehran ( 14 , 15 ) , mashhad ( 16 ) and shiraz ( 17 ) . this study was aimed to report an interesting case of human linguatulosis in the city of kerman in 2013 . this study has future medical implication in precise diagnosis of l. serrata , when nasopharyngeal symptoms are suspected . a 32-year - old woman was admitted to the respiratory tract clinic at the afzalipour hospital of kerman university of medical sciences in the city of kerman , the center of kerman province , south- eastern iran in 2013 . she used to consume raw liver of sheep for many years , a traditional belief for its nutritional values . the last time she ate pieces of raw liver , she felt burning sensation and itching irritation of the upper respiratory mucus membranes in particularly nasopharyngeal region and throat . the condition became worst , gradually within a week , where other symptoms including sneezing , coughing and respiratory discharges appeared , progressively . upon examination by nasopharyngoscopy and bronchoscopy , no foreign bodies were observed . following further coughing , accompanied by blowing of the nasal areas , three worm - like pentastomid were expelled . they were transferred to the department of parasitology and mycology at the school of medicine in kerman university of medical sciences for further differentiation . they were examined under a conventional light microscope and identified as the nymphal instars of linguatula serrata . in close microscopic examination , the head actually consists of the mouth , two pairs of hooks , and surface membrane with spines and marginal segmentation ( fig . the parasite was 4.2 mm in length , appeared whitish with a typical tongue- like , flattened shape , superficially segmented and rounded anteriorly while pointed at the posterior end . cetirizine medicine and flixonase aqueous nasal spray were used for treatment of allergic reaction induced by l. serrata . follow- up examination of the patient showed no symptoms or complaints , with a thankful appreciation and comfortable feeling . linguatulosis due to l. serrata is a cosmopolitan pentastomid , mainly in carnivorous and herbivorous animals ( 3 - 13 ) . human infestations have sporadically been reported from latin americas , africa , asia and europe ( 2 ) . most of the infestation is acquired by ingesting vegetables or water contaminated with pentostome eggs or by consuming under - cooked and raw liver of livestock ( 1 ) . the symptomatic condition of the patient in this report is much like that of marrara or halzoun syndrome caused by l. serrata ( 18 ) , an inflammation and itching of the upper respiratory tract . similar sporadic linguatulosis of human has previously been reported from different provinces of iran ( 14 - 17 ) and other countries ( 18 , 19 ) . interestingly , high prevalence of infestations in dogs and ruminants ( sheep , goats , cattle and camels ) , as definitive and intermediate hosts , respectively , play an important role in epidemiology of human linguatulosis , in this county . these animals as potential source of infection and as a threat , pose an important public health and veterinary concern worldwide , mainly in endemic counties such as iran . physicians should be aware and consider l. serrata infestation in patients with complaints of upper respiratory tract symptoms , especially in endemic areas , where humans consume raw or under - cooked liver or when they are in close contact with domestic and home- reared animals .
human linguatulosis poses an important medical and veterinary concern in endemic countries . 
 animals , as reservoir host , play a major role in transmission of infestation and epidemiology of the disease . 
 this study reports a case of human linguatulosis caused by linguatula serrata in the city of kerman , south - eastern iran . 
 a woman suffering from upper respiratory symptoms is presented . 
 the patient consumed raw liver of sheep who was admitted to the afzalipour university hospital in kerman for the symptoms of upper respiratory tract . in microscopic examination of the nasopharyngeal discharge , l. serrata was detected . 
 this report has future medical implication in precise diagnosis of l. serrata in patients with complaints of nasopharyngeal symptoms .