Why do we not typically see features of rhabdomyolysis or acute kidney injury with idiopathic inflammatory myopathies?  

Because rhabdomyolysis leading to AKI means acute massive necrosis of a large number of muscle fibers with resulting release of myoglobin In blood and precipitation of myoglobin in renal tubules, leading to tubular necrosis. This acute extensive myonecrosis typically does not occur with IIMs, with t...