Chocolate cyanosis

A. Symptoms and signs are caused by decreased blood oxygen content and cellular hypoxia and include headache, dizziness, and nausea, progressing to dyspnea, confusion, seizures, and coma. Even at low levels, skin discoloration ( chocolate cyanosis ), especially of the nails, lips, and ears, is striking. 

Clinical cyanosis (chocolate brown blood) no hypoxic symptoms... 

A. Methemoglobinemia (see p 261) causes cyanosis and dyspnea. Drawn blood may appear dark chocolate brown when the methemoglobin level is... 

GI Tract May cause gastrointestinal irritation with nausea, vomiting, and diarrhea. Methemoglobinemia is characterized by dizziness, drowsiness, headache, shortness of breath, cyanosis with bluish skin, rapid heart rate, and chocolate-brown colored blood. 

The classic presentation is of unexplained cyanosis in the presence of a normal PaOz with brown- or chocolate-coloured blood that does not become red on exposure to oxygen. Skin discoloration can occur in patients who are not anaemic with as little as approximately 10% metFIb. At Fiigh levels of metHb pulse oximeters will tend to read close to 85% regardless of the true level of oxygen saturation. The failure of 100% oxygen to correct cyanosis is also suggestive of methaemoglobinaemia. 

Effects progress from cyanosis (blue baby syndrome) to shortness of breath and eventual asphyxiation (chemical suffocation) as the blood turns chocolate brown. Fortunately, an infant treated in a timely manner with ascorbic acid or methylene blue will experience a complete recovery, and adequate intake of vitamin C provides... 

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