Occult Methemoglobinemia in a Medically-Complex 7-Year-Old Child and the Opportunity for Pharmacist Intervention in Pediatric Emergency Medicine.

Methemoglobinemia is a rare, yet life-threatening disorder that occurs due to an accumulation of methemoglobin in the blood. The clinical presentation often includes dyspnea, cyanosis, and hypoxemia that shows little improvement with the administration of supplemental oxygen. The US Food and Drug Administration (FDA) warns against the administration of benzocaine to those younger than 2 years of age and urges manufacturers to add a statement regarding the possible development of methemoglobinemia to the packaging of any products containing this ingredient. However, providers caring for pediatric patients should recognize that methemoglobinemia may occur in toddlers and children outside of the FDA's specific age warning window and must keep a broad differential for patients presenting with respiratory distress. The objective of this article is to highlight a case of a child subsequently found to have benzocaine-induced methemoglobinemia and emphasize the importance of pharmacists in an emergency medicine setting, particularly in the care of patients with uncommon acute conditions requiring lesser-known pharmacologic treatments.