Sulfites are food preservatives that can cause breathing difficulties in some people
with asthma. They are considered an "asthma trigger" for people who are susceptible
to them because they bring on asthma symptoms such as cough, wheezing, or shortness
of breath. Sulfites are used as a preservative in many food products to prevent them
from spoiling. Some examples of products that contain sulfites include: wine, beer,
dried fruits and vegetables, shrimp, and pickles.