If you know you have allergies, visit an allergist ahead of time to find out what you are allergic to and to receive a prescription for a non-sedating antihistamine. Take the antihistamine the morning of your wedding, not later in the day when symptoms may already have started. Carry a small pack of tissues in your purse for a sudden attack of sneezes as well as antihistamine eye drops to avoid red, itchy eyes in your photographs. If you are having someone do your hair and makeup, be sure they don't use products that may aggravate your allergies. Also, make sure the caterers are able to answer questions from your guests about food ingredients.
Some food allergy reactions can be very severe and even life threatening.
When traveling to and from the church and reception, travel in an air-conditioned car with the windows closed to prevent pollens from triggering your allergies. Limit the amount of time you spend taking outdoor pictures. You may want to consider all indoor pictures. Spend as much time as you can indoors with air conditioning where the air is generally free from pollens and molds. It is not a substitute for professional medical advice.