An Atypical Case of Methemoglobinemia due to Self-Administered Benzocaine

Table 2

The clinical manifestation of methemoglobinemia [1, 2].

%MetHgb	Symptomology
0–3	Asymptomatic and normal level in blood
3–15	Possibly asymptomatic, grayish pallor, mild cyanosis, and low oxygen saturation per pulse oximeter
15–20	Cyanosis and chocolate-brown appearance of blood
20–50	Dyspnea, fatigue, weakness, headache, dizziness, and syncope
50–70	CNS depression, lethargy, seizures, and metabolic acidosis
>70	Severe cyanosis and death