Acute pyelonephritis is a bacterial infection that affects the renal pelvis and kidney. Use the mnemonic SCARRIN' UP to memorize the predisposing factors for acute pyelonephritis.

SCARRIN' UP mnemonic stands for;

Sex (females <40 years, males >40 years)
Catheterization
Age (infant, elderly)
Renal lesions
Reflux (vesciouteral urine relux)
Immunodeficiency
NIDDM, IDDM (Non-insulin dependent diabetes mellitus and insulin dependent diabetes mellitus)
Urinary obstuction
Pregnancy