kawasaki disease ( kd ) , also known as mucocutaneous lymph node syndrome , predominantly affects infants and young children . due to lack of specific diagnostic tests , the diagnosis of kd
however , as an acute systemic vasculitis , kd may be involved in multiple organs and systems , causing unusual manifestations and thus making the diagnosis difficult . here
we report a case of kd which initially manifested as parapharyngeal abscess ( ppa ) , leading to delayed diagnosis .
furthermore , this case included unnecessary surgery and thus the risk of surgical complications was increased .
a previously healthy 3-year - old male patient was admitted into our pediatric department with fever ( up to 39 ) , neck swelling , dysphagia , and drooling for 3 days . on physical examination ,
the patient was toxic and irritable , and showed hyperemic throat , enlarged tonsils and bilateral tender cervical lymphadenopathy .
laboratory investigations revealed white blood count ( wbc ) : 23,800/l ( neutrophils : 79.2% , lymphocytes : 11.6% ) , hemoglobin : 12.7  g / dl , platelet count : 256,000/l and c - reactive protein ( crp ) 210  mg / l .
purulent cervical lymphadenitis was considered and vancomycin ( 40  mg / kg / day ) was prescribed . on the following day , the painful cervical lymphadenopathy did not show any improvement and the patient developed trismus and restricted neck movement . computed tomography ( ct ) of
the neck revealed a 2  cm    1.5  cm low - density lesion in the right parapharyngeal space ( figure 1 : asterisk ) , with peripheral enhancement ( figure 1 : arrow ) as well as multiple lymph node enlargements in the posterior cervical space .
ppa was suspected and the patient was transferred to the otorhinolaryngologic department for surgery . on the 3rd day following admission , the patient developed bilateral bulbar conjunctival injection and red lips . due to the possibility of upper airway obstruction , incision and drainage of the ppa
after surgery , his neck pain and trismus alleviated , however high fever persisted . during the 5th day of hospitalization , the patient manifested fissured red lips and strawberry tongue . on the 6th day , edema of the hands and feet and polymorphous generalized erythematous skin rash appeared .
laboratory investigations revealed wbc : 39,780/l ( neutrophils : 75% , lymphocytes : 18% ) , hemoglobin : 12.3  g / dl , platelet count : 395,000/l , erythrocyte sedimentation rate : 132  mm / h , crp : 171  mg / l , pro - albumin : 72  mg / l , and nonseptic pyuria . despite antibiotic treatment with vancomycin and cefoperazone , the fever persisted .
the patient was transferred back to the pediatric department from the otorhinolaryngologic department on the 8th day following admission . upon re - evaluation of his clinical and laboratory findings ,
the diagnosis of kd was considered and intravenous immunoglobulin ( ivig ) at 2  g / kg along with aspirin at 30 
no coronary artery abnormalities were found on repeated echocardiogram . due to the parapharyngeal operation ,
finally , the patient was discharged on the 20th day of hospitalization , on a low dose of aspirin . during the 2 months of follow - up
neck ct scan showing a hypodense lesion ( asterisk ) in the right parapharyngeal space with peripheral enhancement ( arrow ) .
parapharyngeal abscess ( ppa)-like lesion is a very rare manifestation of kd . to the best of our knowledge , there has only been one similar case reported , occurring in the usa .
, kd can mimic other kinds of deep neck infections , such as peritonsillar abscess , peritonsillar cellulitis , or retropharyngeal abscess ( rpa ) .
the rarity of these presentations often leads to missed or delayed diagnosis and treatment . in this patient , although infection can not be ruled out at the early stage , the fact that blood and throat cultures were negative and there was an excellent response within 24  hours after administration of intravenous immunoglobulin ( ivig ) and aspirin makes the diagnosis of kd presenting as a parapharyngeal abscess - like lesion more plausible than an infection coexisting with kd . in this case , the boy manifested like infectious ppa at the beginning : fever , dysphagia , neck rigidity , remarkably elevated wbc and crp , and an abscess - like lesion on the ct .
similarly , in most of the previously reported kd cases mimicking rpa , fever and deep neck infection like - symptoms were the only clinical findings at admission .
after carefully comparing children with kd accompanied by retropharyngeal edema to , those with rpa , nomura et al concluded that close attention to core manifestations but not laboratory examinations of kd helps clinicians to differentiate these 2 conditions . obviously , our findings agree with nomura 's report . in our opinion , both pediatricians and otolaryngologists should draw lessons from this case .
indeed , the patient had already developed bilateral bulbar conjunctival injection and red lips on the 3rd day following admission . from this case
we need to realize that ppa - like lesion can be the initial presentation of kd .
therefore , when some signs of non - septic vasculitis emerge , pediatricians must carefully observe for other signs of kd .
otolaryngologists are excellent at managing deep neck infections , but not at diagnosing and treating kd . in this case , although the patient had already met the criteria of kd on the 6th day following admission , proper diagnosis was not made by surgeons in the otorhinolaryngologic department .
treatment with ivig and aspirin was initiated after the patient was transferred back to the pediatric department .
to avoid delayed diagnosis , otolaryngologists should be aware of the manifestations of kd and include it as a routine differential diagnosis for ppa .
the exact pathophysiology through which kd leads to ppa is unknown . as with kd - associated rpa , ppa in kd
histopathological study of cervical lymphadenopathy in kd revealed non - purulent inflammation and ischemic necrosis due to fibrin thrombi in small vessels of affected lymph nodes .
inflammatory infiltration of the lymph node capsule was present in most of the affected cervical lymph nodes .
mri scan found that affected lymph nodes had capsular and hilar but not parenchyma enhancement . in this case , we speculate that the abscess - like lesion originated from a lymph node : the hypodense central area found by ct ( figure 1 : asterisk ) may be caused by nonseptic inflammatory edema , and peripheral enhancement ( figure 1 : arrow ) may be due to capsule inflammatory infiltration .
future evidence is needed to confirm this pathological hypothesis . how to treat kd mimicking deep neck abscess is a challenging question . in a review of 24
previously reported kd cases with rpa - like lesion , all of them were unresponsive to antibiotics .
seven of the 24 cases received surgical aspiration or drainage but no abscess or bacterial infection evidence was found .
fever and other symptoms resolved rapidly after the administration of ivig and aspirin in all of the 24 patients . as the deep neck abscess - like lesion
is formed by local inflammation and edema under the condition of systemic vasculitis , it will be absorbed and disappear when systemic vasculitis is controlled by ivig and aspirin .
therefore , in our opinion , kd mimicking deep neck abscess is not an indication for surgery .
operations should not be arranged hastily for these patients , as surgical complications , such as incision infection in our case , can be thusly avoided . for those patients with upper airway compression due to the abscess
future well - controlled trials are needed to prove the safety and effectiveness of non - surgical treatment for kd mimicking deep neck abscess . in conclusion
, both pediatricians and otolaryngologists should keep in mind that , in addition to bacterial infection , kd can cause ppa - like lesion .
careful observation for major signs of kd during the clinical course can help to achieve an early and correct diagnosis .
 abstractparapharyngeal abscess ( ppa)-like lesion is a very rare manifestation of kawasaki disease ( kd ) . here we report a chinese case of kd initially mimicking ppa , which is the first one reported in asia.a 3-year - old male patient presented with fever , drooling , and bilateral painful cervical lymphadenopathy for 3 days . 
 chest x - ray and echocardiogram were normal . with substantial elevation of white blood count and c - reactive protein , 
 purulent cervical lymphadenitis was considered . 
 symptoms did not improve after treatment with vancomycin , and the patient further developed trismus and restricted neck movement . 
 neck ct revealed a 2    1.5  cm hypodense lesion in the right parapharyngeal space with peripheral enhancement . 
 ppa was suspected and on the 3rd day following admission , the patient received surgical incision and drainage . 
 one milliliter of serous fluid was drained without bacterial growth on cultures . 
 fever persisted after surgery . 
 as the clinical course proceeded , additional major signs of kd gradually evolved , and on the 6th day following admission the patient completely fulfilled the diagnostic criteria for kd . 
 rapid clinical improvement was observed following treatment with high - dose immunoglobulin and aspirin . due to the parapharyngeal operation , 
 the patient was fed milk through a nasogastric tube for 15 days . 
 his neck incision became infected but healed gradually following dressing change and antibiotic treatment . 
 currently he remains asymptomatic during regular follow - up and repeated echocardiograms are normal.both pediatricians and otolaryngologists can learn from this case that kd may initially manifest as ppa . 
 careful observation for major signs of kd during the clinical course can help to achieve a prompt and correct diagnosis . 
 thus , unnecessary surgery and cardiac complications of kd may be avoided . 
INTRODUCTION
CASE PRESENTATION
DISCUSSION