Unusual presentation of Acquired Methaemoglobinemia

We describe the case of a child with acquired methaemoglobinemia. As the history was strongly suggestive of foreign body aspiration, a rigid bronchoscopy was initially performed under general anaesthesia followed later by successful treatment with methylene blue. The results of pulse oximetry in methaemoglobinemia are discussed and the reasons for the erroneous readings are explained.