An incidental finding of congenital methaemoglobinaemia in a patient with an allergy

Kga Kumara,S Suganthan,T Kumanan

doi:10.4038/cmj.v58i2.5689

Abstract

A 23-year old unmarried woman who had beenapparently well until three days prior to admission haddeveloped urticarial rash, cough and difficulty in breathingafter eating beef. On admission, she was comfortable atrest, not pale, and had central cyanosis. There was nofinger clubbing or ankle oedema. She was haemodyna-mically stable, heart sounds were normal and there wereno murmurs. Respiratory system examination was unre-markable except for occasional ronchi on auscultation.Her oxygen saturation on room air was 85% and it didnot improve with additional oxygen supplementationvia face mask.She had a good clinical recovery from the allergicreaction to beef and became asymptomatic in two days.However the central cyanosis was persistent and heroxygen saturation on room air was persistently low andremained around 85% despite clear lung fields. This war-ranted further evaluation.ECG, chest radiograph and other initial bloodinvestigations including full blood count and ESR werenormal. Blood gas analysis was performed while hersaturation was 85% on room air. It showed, pH 7.46, pCO

Highlights

A 23-year old unmarried woman who had been apparently well until three days prior to admission had developed urticarial rash, cough and difficulty in breathing after eating beef
Co-oximetry is the gold standard for diagnosis
Congenital methaemoglobinaemia due to NADHcytochrome b5 reductase 3 deficiency is an autosomal recessive disorder. It present as two distinct phenotypes, type I and type II

Summary

Introduction

A 23-year old unmarried woman who had been apparently well until three days prior to admission had developed urticarial rash, cough and difficulty in breathing after eating beef. She was comfortable at rest, not pale, and had central cyanosis. Her oxygen saturation on room air was 85% and it did not improve with additional oxygen supplementation via face mask. The central cyanosis was persistent and her oxygen saturation on room air was persistently low and remained around 85% despite clear lung fields.

Results

Conclusion