What are common wasp sting allergic reactions?

Local. Most sting reactions cause local symptoms: swelling, itchiness, redness. Very rarely can one see a patient develop systemic allergic reaction.
Wasp allergic rxns. Enzymes in wasp venom break down cell walls ; degranulate mast cells which in turn leads to release of histamine resulting in symptoms like itching, swelling ; pain.Seek medical care for milder allergic reactions: swelling of > 4 inches, nausea, GI cramps, diarrhea.Throat, airway, mouth swelling or difficulty breathing? Call 911!