Sudden Infant Death Syndrome - Differential Diagnosis

Differential Diagnosis

Some conditions that are often undiagnosed and could confused with or comorbid with SIDS include:

• medium-chain acyl-coenzyme A dehydrogenase deficiency (MCAD deficiency);
• infant botulism;
• long QT syndrome (accounting for less than 2% of cases);
• Helicobacter pylori bacterial infections;
• shaken baby syndrome and other forms of child abuse;
• overlying.

For example, an infant with MCAD deficiency could have died by "classical SIDS" if found swaddled and prone with head covered in an overheated room where parents were smoking. Genes indicating susceptibility to MCAD and Long QT syndrome do not protect an infant from dying of classical SIDS. Therefore, presence of a susceptibility gene, such as for MCAD, means the infant may have died either from SIDS or from MCAD deficiency. It is currently impossible for the pathologist to distinguish between them.

A 2010 study looked at 554 autopsies of infants in North Carolina that listed SIDS as the cause of death, and suggested that many of these deaths may have been due to accidental suffocation. The study found that 69% of autopsies listed other possible risk factors that could have led to death, such us unsafe bedding or sleeping with adults.