(P54) From Minion to Smurf: A Case of Acquired Methemoglobinemia

Chief Complaint : Severe Depression; Suicide Attempt by Ingestion

History of Present Illness : A 13-year-old female with a history of severe depression (on Zoloft as of four weeks before this visit), self-harm via cutting, previous suicide attempt, and blindness of left eye presented for a suicide attempt by ingestion of pyridium. She had multiple vomiting episodes with continued nausea and abdominal pain after ingestion. The patient denied alcohol use and endorsed THC use. A review of the systems was positive for abdominal pain, nausea, vomiting, and suicidal ideation. She denied shortness of breath, light-headedness, headaches, constipation, diarrhea, and color change.

Pertinent Physical Exam: Skin appeared yellow on soles of hands, feet, and around the mouth. Tachycardia was present.

Pertinent Laboratory Data: VBG, CBC, BMP, and lactic acid were within normal limits. The urine drug screen was negative for all substances except for THC. CK was 57. Methemoglobin level was 1.1.

Repeat methemoglobin level was 25.2 (10 hours after ingestion).

Case Discussion: Few cases of methemoglobinemia caused by Pyridium, or phenazopyridine, have been reported over the past three decades (Murphy, 2018).
Patients commonly present with clinical cyanosis despite a normal arterial pO2. Although severity can vary greatly, other symptoms can include pallor, fatigue, central nervous system depression, weakness, headache, metabolic acidosis, seizures, and coma (Murphy, 2018; Lolascon et al., 2021). In this case, the patient's history of pyridium ingestion and subsequent presentation with delayed-onset cyanosis prompted the evaluation of methemoglobinemia, which was confirmed by significantly elevated methemoglobin levels. The delayed onset of symptoms emphasizes the importance of monitoring patients for several hours after exposure to potentially causative agents, as methemoglobinemia can develop over time.
Moreover, this case highlights the importance of interdisciplinary collaboration in managing patients with psychiatric comorbidities and suicidal ideation. The patient was initially evaluated and managed by the ED team, pharmacologic toxicology, and psychiatric response center, with subsequent transfer to the medical floor for further monitoring. The involvement of multiple specialties, including toxicology, psychiatry, and pediatrics, allowed for timely recognition and management of methemoglobinemia and ongoing management of the patient's psychiatric comorbidities. This case also demonstrates that methemoglobinemia can resolve without methylene blue administration, a standard treatment for methemoglobinemia given that the main morbidity risk is hypoxia. Supportive measures such as oxygen therapy and monitoring for the resolution of cyanosis can be sufficient, as seen in this case.

References and Acknowledgements (Optional): Iolascon, A, Bianchi, P, Andolfo, I, et al. Recommendations for diagnosis and treatment of methemoglobinemia. Am J Hematol. 2021; 96( 12): 1666- 1678. doi:10.1002/ajh.26340