This case of idiopathic eosinophilic polymyositis, to our knowledge, is unique because it is a rare cause of severe rhabdomyolysis without another organ involvement. atrophy with eosinophilic infiltrates (arrow) in the endomysium. 3. Discussion The present case illustrates an unusual cause of rhabdomyolysis. The etiologies of rhabdomyolysis are subdivided into four categories: exertional, nontraumatic SPD-473 citrate exertional normal muscle, nontraumatic exertional abnormal muscle, and nonexertional. Our patient had an inflammatory myopathy, which is a nonexertional subtype. The inflammatory myopathies can be further divided into the rare eosinophilic myopathies (EM) and the more common noneosinophilic myopathies (NEM) like noneosinophilic polymyositis, dermatomyositis, and inclusion body myositis . There are different classification systems to help diagnose these inflammatory myopathies but without biopsy and positive autoantibodies, identification remains a challenge . Eosinophilic myositis (EM) usually presents between the ages of 14 and 70 and is twice as common in females compared to males . The most common presenting symptoms include a gradual onset of muscle pain, edema of the upper and/or lower extremities, muscle weakness, and joint pains . Other signs, symptoms, and lab findings of EM are listed SPD-473 citrate in Tables ?Tables11 and ?and2.2. This slowly progressive myopathy mostly causes proximal muscle weakness with a marked increase in creatinine kinase. Table 1 Signs and symptoms of eosinophilic myositis . EchinococcusTaenia soliumToxoplasma gondii /em ), viruses (EBV and coxsackie), inflammatory myopathies (dermatomyositis, polymyositis), and systemic diseases (Churg-Strauss syndrome) . Other less common etiologies like muscular dystrophies (calpainopathy  and Becker Disease ), toxic exposures to L-tryptophan , toxic oil syndrome, malignancy, and EM as a component of idiopathic hypereosinophilic syndrome (HES) can also have eosinophilic predominant myositis . Other drugs associated with myopathy and eosinophilia include cimetidine, phenytoin, and penicillamine . Once all the above etiologies have been considered, and no cause has been identified, idiopathic eosinophilic myositis can be diagnosed as in our case. Eosinophilia associated myopathy is categorized into 3 subtypes: focal eosinophilic myositis, eosinophilic perimyositis, and eosinophilic polymyositis (Table 3). Focal EM usually causes lower extremity pain and calf swelling. Eosinophilic perimyositis generally causes myalgias and moderate proximal muscle weakness. Labs may show normal creatinine kinase levels. Eosinophilic polymyositis is usually more commonly a systemic disease with frequent cardiac, lung, or gut involvement [6, 13]. Interestingly, peripheral eosinophilia is not needed to diagnose any of the above entities [2, 15]. Clinically, our patient had severe muscle weakness, elevated CPK levels, a high degree of peripheral eosinophilia, and the need for steroids for symptomatic involvement. Histologically, her muscle biopsy revealed widespread eosinophilic infiltration consistent with a diagnosis of eosinophilic polymyositis. Table 3 Proposed criteria for diagnosis for eosinophilic myositis . thead th align=”left” rowspan=”1″ colspan=”1″ ? /th th align=”left” rowspan=”1″ colspan=”1″ Focal eosinophilic myositisa /th th align=”left” rowspan=”1″ colspan=”1″ Eosinophilic polymyositisb /th th align=”left” rowspan=”1″ colspan=”1″ Eosinophilic perimyositisc /th /thead Major(1) Pain and calf swelling (other muscles can be affected) br / (2) Deep eosinophilic infiltration with muscle fiber invasion and necrosis on SPD-473 citrate muscle biopsy (1) Proximal weakness Rabbit Polyclonal to GFR alpha-1 affecting limb girdle muscles (may be severe) br / (2) Widespread deep infiltration of eosinophil into muscles, with eosinophilic cuffing, on histology. Myonecrosis and endomysium inflammation usually +ve. If ?ve deposition of MBP should be demonstrated by immunostain(1) Myalgia, proximal moderate weakness br / (2) Eosinophilic infiltrate confined to fascia and superficial perimysium, absence of myofiber necrosis hr / Minor (1) CPK and aldolase br / (2) MRI or EMG evidence of focal myositis br / (3) Absence of systemic illness br / (4) Eosinophilia 0.5 109/L (1) CPK and aldolase br / (2) Eosinophilia 0.5 109/L br / (3) Systemic illness with frequent cardiac involvement br / (4) Steroids are needed (1) Absence of systemic manifestations br / (2) Normal CK and aldolase levels br / (3) Eosinophilia 0.5 109/L hr / ExcludeDVT, cellulitis, parasitic infection HES, cell T clonality, DM, vasculitis (CSS), drugs, calpainopathy, parasitic infections Toxic oil syndrome, myalgia-eosinophilia, exposure to inorganic or organic substances hr / TreatmentNo steroid treatment required. Symptoms resolve spontaneouslyPrednisone 0.5C1?mg/kg/day is the treatment of choiceRarely requires steroid.