document: the ticks that belong to the genus amblyomma are large , ornate , longirostrate blood - feeding ectoparasites of a wide variety of vertebrates . 
   amblyomma testudinarium is one of the species that has been frequently reported to bite humans in asian countries . 
   usually , only a few ticks attached to and fed on a human , but 3 reported cases were infested with more than 100 larval ticks . in malaysia , a patient repeatedly infested with a. testudinarium was reported . 
   it is well known that a. testudinarium is distributed in korea . however , human infestation of a. testudinarium tick is rare , with 2 previously reported cases in elderly korean persons . 
   we report here an additional case of perianal infestation with a. testudinarium and provide histopathologic observations of its attachment to the skin . 
   a 73-year - old korean man with a round nodule in the left perianal area presented to our clinic in september 2010 . 
   the solitary nodule had been found about 2 weeks before admission and was not accompanied by hemorrhage and pain . 
   he recalled a trip to a water reservoir located at yeonggwang - gun ( between 35 to 36 north latitude ) , a rural county in jeollanam - do province , south korea 1 month before the presentation . at that time 
   , he defecated in the sitting posture on the grass near the water reservoir and felt the pain of sting around anus . 
   gross appearance of the tick bite site was characterized by a mild swelling and erythema . 
   the patient agreed to surgical treatment of the skin lesion to remove the perianal tick . 
   1a ) , placed in 10% buffered formalin and submitted for evaluation . during histologic processing , the tick was accidentally separated from the biopsied skin tissue . 
   it was 25 mm in length and 18 mm in width and engorged with blood meal ( fig . 
   the pedipalps had a long article ii with approximately 2.5 times as long as the article iii . 
   the denticles of the inner file were much smaller than those of the other files . 
   the ornamented scutum was relatively small , and its punctuations were dark brown or brownish - black spots on a pale yellow background ( fig . 
   the eyes were located on the lateral edges of the scutum but not projecting ( fig . 
   2c ) and located on the ventrolateral surface posterolaterally to the coxa iv ( fig . 
   the genital aperture was located at the level between the coxa i and coxa ii ( fig . 
   the anus was located at the level posterior to the spiracular plates and embraced by y - shaped anal groove posteriorly ( fig . 
   the coxa i had 2 subequal spurs , and the external spur was slightly longer than the internal spur ( fig . 
   the coxae ii and iii had a single salient ridge - like spur ( fig . 
   the coxa iv had a single spur which was longer than those of the coxae ii and iii ( fig . 
   microscopical examinations revealed an intense skin reaction at the site where the tick had attached . 
   due to deep penetration , the pathological changes were observed through all skin layers from the epidermis to the subcutaneous fat layer . in a low power field , 
   the lesion comprised of central amorphous eosinophilic material and surrounding inflammatory cell infiltrations ( fig . 
   4 ) . at the site of the tick bite , a small epidermal defect and invaginated squamous epithelium were seen . 
   the epidermal defect was about 1.8 mm in width and adjacent epidermis revealed parakeratosis , hyperkeratosis , and mild spongiosis . 
   scattered inflammatory cells , mainly neutrophils , were seen in the epidermis . in the dermis , a characteristic feeding lesion was formed immediately beneath the attachment site . 
   it was composed of 2 different portions ; superficial perirostral portion and deep cavitary portion ( fig . 
   the perirostral portion was 2.1 mm in depth and much wider at the distal part than at its entrance . 
   the cement , however , was found slightly at the dermal entrance of the tick mouthparts but not on the surface of the epidermis . 
   it was lamellate and had projections into the adjacent tissue in some areas ( fig . 
   it was relatively small and filled with purulent exudates containing inflammatory cells and erythrocytes ( fig . 
   a dense and mixed cellular infiltrate was also noted around the feeding lesion and extended into neighboring dermis and subcutaneous tissues . 
   however , there were very few inflammatory cells immediately adjacent to the site which abutted the eosinophilic cement ( fig . 5 ) . 
   there was no evidence of infection or residual disease up to 1 month after surgical removal 
   of the tick . 
   among the hard ticks , only 3 genera , ixodes , haemaphysalis , and amblyomma have been recorded from humans in the republic of korea . 
   this means that it does not belong to the genus ixodes which is the most common cause of human tick - bites in korea . 
   the pedipalps of the present specimen are slender and longer than the basis capituli , and their second segment is not salient laterally . 
   the eyes and fastoons are present , the small scutum is ornate , and the spiracular plate is comma - shaped 
   the denticles of the inner file are much smaller than those of the other files . 
   the spur of the coxa iv is longer than those of coxae ii and iii . 
   the tarsi iii and iv have 2 distinct subapical ventral spurs . from the above observations , this tick is easily distinguished from amblyomma nitidum and amblyomma geoemydae which are distributed in the far east asia . 
   therefore , our tick has been identified as a female adult of a. testudinarium based on morphological characteristics . 
   the warm temperature and subtropical vegetation fauna are known to be a proper environmental condition for a. testudinarium . 
   thus , this tick is more common in the tropic areas , including south east asia and indian peninsula . in japan , 
   the closest geographical neighbor to korea , a. testudinarium is one of the most common ticks infesting humans and especially important in southwestern areas . 
   in korea , it is also distributed in jeju island and the southern coastal area of the mainland . 
   the first human case was reported in suncheon city ( 35 north latitude ) , a southern coastal area of jeollanam - do . 
   the second case occurred in tongyeong city ( below 35 north latitude ) , southern coastal area of gyeongsangnam - do . in the present case , 
   the patient was infested in yeonggwang - gun , a western coastal area of jeollanam - do . 
   therefore , a. testudinarium extends the geographic range of distribution from the southern coastal area more northwards to the southwestern costal area ( below 36 north latitude ) of the korean peninsula . 
   after a site for feeding has been chosen , ticks embed their anterior part calling capitulum into the skin . the capitulum is composed of 4 different components ; the palps , chelicerae , hypostome , and basis capituli . 
   ticks attached on the skin lacerate the epidermal layers using the chelicerae which are paired appendages for cutting , ripping , and tearing skin . 
   after epidermal laceration , ticks insert midline mouthparts ( the chelicerae and hypostome ) into the opening at a depth that varies by species . in the present case , 
   the depth of penetration is similar to the length of the hypostome which has been deeply inserted into the dermis . 
   however , the width of epidermal laceration is not similar to that of mouthparts but similar to that of the basis capituli . 
   this means that the basis capituli is embedded shallowly in the host epidermis during the feeding period . 
   the histopathology of skin responses to infection with the present female a. testudinarium shows that the dermis is infiltrated with various inflammatory cells associated with both acute and chronic reactions , i.e. , lymphocytes , neutrophils , histiocytes , and eosinophils . 
   these inflammatory findings are similar to those reported by other researchers on amblyomma species experimentally and naturally infested in various vertebrate hosts . around the lesion abutting the cement , we observed an interesting area having relatively few inflammatory cells . 
   this cell - free area is called the paucicellular zone . the biologic factors causing a zone of minimal cellular inflammation 
   are not exactly known but are likely due to the anti - inflammatory effects of the tick saliva . according to the study on the effects of tick saliva and salivary gland extracts , this paucicellular zone might reflect tick - induced suppression of cellular migration into the injury site as a result of saliva constituents suppressing the movement of cells into the feeding lesion . 
   the salivary glands of hard ticks secret eosinophilic cement material that help attachment of the tick to the host for the feeding period . 
   it is well known that there is considerable difference in the distribution of the cement within the host tissue . 
   generally , ixodids with long mouthparts ( longirostrate ticks ) penetrate the skin deeply to the dermis and have a perirostal secretion of the cement . 
   ixodids with short mouthparts ( brevirostrate ticks ) have a copious superficial secretion of the cement which spreads over the skin . 
   amblyomma and hyalomma are longirostrate ticks with relative long mouthparts . in the present amblyomma case , 
   eosinophlic cement was found mostly in the perirostral portion but little on the skin surface .
summary: a perianal tick and the surrounding skin were surgically excised from a 73-year - old man residing in a southwestern costal area of the korean peninsula . 
   microscopically a deep penetrating lesion was formed beneath the attachment site . 
   dense and mixed inflammatory cell infiltrations occurred in the dermis and subcutaneous tissues around the feeding lesion . 
   amorphous eosinophilic cement was abundant in the center of the lesion . 
   the tick had y - shaped anal groove , long mouthparts , ornate scutum , comma - shaped spiracular plate , distinct eyes , and fastoons . 
   it was morphologically identified as a fully engorged female amblyomma testudinarium . 
   this is the third human case of amblyomma tick infection in korea .