Alpha-gal syndrome is diagnosed by detecting specific IgE to galactose-alpha-1,3-galactose in serum, paired with a compatible delayed-reaction history.
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Steps
schema.org/HowTo
01
Order a serum specific IgE for galactose-alpha-1,3-galactose (alpha-gal).
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Levels above 0.1 kU/L are considered positive; clinically significant levels are usually higher.
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Pair with history: delayed (3-6 hour) reactions to mammalian meat or dairy.
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A positive IgE without symptoms is sensitization, not syndrome — many people are sensitized after lone-star bites.
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Repeat testing every 6-12 months can track declining IgE in patients avoiding further bites.