An Unusual Case of Metabolic Acidosis: The GAP and Urine are the Clues

Metabolic acidosis is a common disorder in hospitalized patients, even more in the intensive care unit, often representing a diagnostic challenge. It is classified as normal or high anion gap metabolic acidosis. High Anion Gap Metabolic Acidosis (AGMA) can result of increase in unmeasured anions such as lactic acid, keto acids, alcohol intoxication or more rarely pyroglutamic acid. Case presentation: A 19-year-old woman with no medical history presented to the emergency department due to bullous skin lesions with extensive involvement of the body surface suggestive of Steven Johnson Syndrome (SJS).During her stay in the ICU she presented acute endocarditis by methicillin -sensitive Staphylococcus aureus treated with cloxacillin, also she received acetaminophen for fever. After two months of admission, nephrology unit was consulted for hypokalemic metabolic acidosis with high requirements of intravenous sodium bicarbonate over 1000 mEq/day. High anion gap metabolic acidosis, hypokalemia, uroanalysis with elevated pH and positive urinary anion gap were indentified. Conclusion: AGMA by accumulation of pyroglutamic acid is a rare and underdiagnosed condition. It should be considered in all patients with unexplained AGMA who have risk factors that predispose them.