What do high iga serum mean? does it mean allergies?

No, IgE = allergies: A high ige is associated with allergies, parasitic infections and some rarer medical conditions. A slightly high IgA is a nonspecific finding and may not be clinically significant. If it's extremely high, like ten times normal, it could mean a plasma cell abnormality, like multiple myeloma. Autoimmune diseases may also cause IgA to become elevated. Ask an immunologist to evaluate you if concerned.