Botulism laboratory findings

Clinical diagnosis of botulism is confirmed by specialized laboratory testing that often requires days to complete. Routine laboratory test results are usually unremarkable. Therefore, clinical diagnosis is the foundation for early recognition of and response to a bioterrorist attack with botulinum toxin, and all treatment and management decisions should be made based on clinical diagnosis.

Lab studies

Lab tests should not be relied upon for diagnosis of botulism. The diagnosis will be done by a physical exam.

• The typical routine lab tests, such as CBC, electrolytes, LFTs, urinalysis, will not be helpful for botulism.
• Cerebrospinal fluid tests will basically be normal, but there might be a bit of protein elevation.
• A normal Tensilon test helps to differentiate botulism from myasthenia gravis; borderline positive tests can occur in botulism.
• Normal CTs and MRIs help to rule out CVA.
• Laboratory confirmation is done by demonstrating the presence of toxin in serum, stool, or food, or by culturing C. botulinum from stool, a wound or food.
• Laboratory testing may take hours or days. Initial diagnosis and appropriate treatment depend on clinical diagnosis through a thorough history and physical examination.

References