pyomyositis is a primary pyogenic infection of skeletal muscle , an uncommon cause of musculoskeletal infection . although relatively common in tropical areas , it is very rare in temperate areas1 .
in contrast , pyomyositis is observed in immunodeficient hosts , particularly in the human immunodeficiency virus ( hiv ) infected condition2 . in nonhiv infected cases ,
skeletal muscle tissue is resistant to bacterial infection , even in the severe bacterial septic condition3 . in approximately 80% of cases ,
the location of the infection is unifocal , and the lower extremities , especially the thigh , are the most common site2 . in the early stages of pyomyositis , there are no typical features of this disease .
because of its rarity , it is often misdiagnosed as muscle hematoma , cellulitis or neoplasm4 .
therefore , prompt imaging procedures , aggressive surgical interventions and appropriate antibiotic therapy are very important to cure this disease without any complications . here
, we report a case of a japanese woman who developed multiple abscesses , which were , surprisingly , disseminated over 30 parts throughout the body , under poorly controlled diabetic conditions accompanied by ketoacidosis , but was successfully treated with prompt and appropriate therapy .
a 26yearold woman was referred to kawasaki medical school hospital , kurashiki , japan , because of a high fever and right thigh pain .
she had mild pain of the right thigh , a sense of thirst and general fatigue .
furthermore , her bodyweight reduced by 6  kg during 2  weeks , and severe thigh pain , and highgrade fever developed and progressively worsened .
she had untreated type  2 diabetes , but did not have any history of trauma or illicit drug use .
her grandmother had adultonset type  2 diabetes , but except for this there was no family history of diabetes including maturityonset diabetes of the young and mitochondrial diabetes . on admission ,
her body mass index was 23.0  kg / m ( height 156  cm and body weight 56  kg ) .
emergent computed tomography ( ct ) showed a giant mass in the right adductor muscle ( figure  1a , b ) .
the drastic elevation of plasma glucose ( 470  mg / dl ) and glycated hemoglobin levels ( 15.2% ) were shown with severe ketoacidosis . despite prehospital administration of insulin ( total 50  u ) and bicarbonate , blood gas analysis still showed metabolic acidosis ( ph  7.339 , hco3 10.9  meq / l , paco2 20.8  mmhg , pao2 107.5  mmhg , base excess 12.8  meq / l , lactate 1.22 
meq / l under oxygen inhalation 2  l / min by nasal cannula ) .
leukocytosis and an increased creactive protein ( 28.21  mg / dl ) were also observed .
renal and liver function , serum creatinine kinase , and myoglobin levels were not elevated .
( a , b ) computed tomography with contrast enhancement in the right thigh on admission . ( a ) frontal slice .
( c ) disseminated abscesses throughout the patient 's body including the kidney and muscle ( on day  7 ) .
based on these findings , we diagnosed this patient as primary pyomyositis , and immediately started broadspectrum antibiotics therapy ( doripenem 3.0  g / day , clindamycin 1200  mg / day ) .
aggressive hydration with saline ( 4.5  l / day ) and intravenous  continuous insulin infusion was immediately started .
furthermore , we carried out surgical drainage and removed 700  ml of  yellowish pus .
surprisingly , the followup ct showed multiple pyomyositis disseminated over 30 parts throughout her body , as well as a kidney abscess ( figure  1c ) .
we immediately restarted clindamycin , and changed fulconazole to micafungin with additional percutaneous renal drainage .
we used broadspectrum antibiotics and an antifungal drug intravenously for a total of 66  days .
there was no clear evidence of osteomyelitis , which is closely associated with pyomyositis , but in consideration of the possibility of osteomyelitis , we decided to carry out longterm antibiotics and antifungal therapy .
indeed , despite a good clinical course , lowgrade fever and persistent mild elevation of crp ( approximately 1.5  mg / dl ) were observed .
therefore , we continued antibacterial and antifungal agents until the normalization of these infectious markers . in the findings of followup ct with the enhancement , the origin bulky abscess in the adductor muscle and systemic intramuscular abscess completely disappeared ( figure  2 ) . on day  66 of the hospitalization , when the value of creactive protein remained within the normal range for 7  days , we stopped all intravenous agents .
complete disappearance of origin and disseminated abscesses . left panel , computed tomography on admission or day  7 ; right panel , computed tomography on day  96 .
it is known that skeletal muscle is resistant to bacterial infection , but under various immunodeficient conditions , such as severe lymphopenia with hiv infection or diabetic ketoacidosis , the host 's defense system against microbiota is destroyed , which easily leads to opportunistic infection .
indeed , there is a close relationship between diabetes itself and the incidence of serious infections5 , 6 , especially sepsis7 .
in addition , because of its rarity , the accurate and timely diagnosis of pyomyositis is challenging . in the present patient ,
severe hyperglycemic state with diabetic ketoacidosis and severe infectious signs led to the diagnosis of pyomyositis . furthermore , typical ct imaging of the bulky abscess in the right adductor muscle was helpful for the diagnosis .
to the best of our knowledge , there have been no reports showing as many as 30 disseminated abscesses .
because there seemed to be no other additional immunodeficiency cause , we assume that the delay of the visit to the medical institution was the main cause of pyomyositis observed in this patient .
stage  1 is the invasive stage where local symptoms and lowgrade fever are observed , but other physical findings are  typically absent .
however , only a minority of patients ( < 2% ) visits a medical institution  at this stage1 .
stage  2 is the suppurative stage with abscess formation . around 23  weeks after the initial onset , patients complain about progressive fever and severe pain of the affected sites .
stage  3 is the late stage , where sepsis and dissemination of the infection are observed if the abscess remains untreated in the previous stages1 .
this progressive stage can be occasionally associated with lethal conditions , especially septic shock , multiple organ failure and rhabdomyolysis6 , 8 .
our patient was very afraid of undergoing all treatment , and hesitated to visit a medical institution .
we believe it is likely that such a delay progressed the pyomyositis in this patient to the most severe and lifethreatening condition .
therefore , it would be very difficult to save her life , if the only one piece of the following situation is missing : precise and timely diagnosis , intensive surgical approach , longstanding antibiotics therapy , and general supportive care . as observed in the present patient
, staphylococcus aureus is the most common ( approximately  70% ) causative bacteria in both tropical and temperate conditions4 .
treatment of pyomyositis depends on the stage of the disease . in the invasive stage ,
a key feature of prognosis of pyomyositis is recurrence , but it is uncommon ( < 30% of all cases ) .
the mortality rate is < 1.5% in the early stage , but it becomes as high as 15% in the late stage10 .
therefore , we have to continue antibiotics and antifungal agent for a long enough period .
in fact , the present patient was successfully  treated with surgical interventions , in combination with longstanding broadspectrum antibiotics and antifungal therapy .
fortunately , during the longstanding broadspectrum antibiotics and antifungal therapy , there were no adverse events including the appearance of resistant bacteria , pseudomembranous colitis , liver dysfunction and electrolytes abnormalities .
pyomyositis is a rare infectious disease , but physicians should be aware of its possibility in poorly controlled diabetic patients .
in addition , the present case strongly suggests that we should continue appropriate therapies until the complete disappearance of abscesses .
 abstractprimary pyomyositis is a pyogenic and uncommon infection of skeletal muscle , which is mainly observed in tropical areas and/or human immunodeficiency virus patients . in nonhuman immunodeficiency virus 
 infected patients , the most common cause is diabetes mellitus . because of its rarity , the accurate diagnosis is often challenging . 
 staphylococcus aureus is the most common causative bacteria . according to the severity 
 , pyomyositis is divided into three stages , and the late stage is occasionally lethal . 
 the present case was compatible with the most advanced stage . 
 therefore , it was very difficult to save her life without precise and timely diagnosis . furthermore , in the invasive stage , surgical drainage and broadspectrum antibiotics should be given for a long enough period . 
 here , we report a case of a japanese woman who developed disseminated abscesses under poorly controlled diabetic conditions accompanied by ketoacidosis , but was successfully treated without any sequelae . 