Diagnostic Approach to a Cyanotic Child

Cyanosis refers to a condition where the skin and mucous membrane assume a blue-purple color as a result of reduced hemoglobin concentration above 5 g/dL. While it may be the indicator of an important disease related to the cardiovascular, pulmonary or central nervous system, it may also develop with methemoglobinemia. This review discusses the approach and differential diagnosis for patients presenting with cyanosis in the light of literature