[Diagnostic and treatment difficulties in kidney damage in the patient with generalized sarcoidosis during COVID-19. Case report].

The presented clinical observation reflects the difficulties of differential diagnosis of progressive kidney damage in a patient with sarcoidosis who has undergone a new coronavirus infection. The differential circle included interstitial nephritis as an exacerbation of the underlying disease, acute drug-induced kidney injury, acute glomerulonephritis. Nephrobiopsy confirmed the diagnosis of acute sarcoid tubulointerstitial nephritis with acute tubular necrosis. Timely administration of corticosteroids led to the control of the sarcoidosis process, restoration of kidney function.