It depends on what you're allergic to, and where you live.
If you have seasonal allergies or hay fever, tree pollens can trigger symptoms in the late winter or spring. Ragweed releases pollen in the summer and fall. The specifics also depend on where you live. Allergy season can start as early as January in Southern states and linger into November.
It is possible that the main title of the report Anaphylaxis is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.