Histamines cause throat allergy symptoms

Allergens cause the production of immunoglobulin E and when they are overproduced, chemicals like histamines cause inflammation and the typical throat allergy symptoms. This is how the immune system becomes misguided and primed to cause an allergic reaction when stimulated by an allergen.
Hay fever (allergic rhinitis) is the most common of the allergic diseases. Year round or perennial allergic rhinitis is usually due to indoor allergens, such as dust mites or molds. Throat allrgy symptoms result from the inflammation of the tissues that line the inside of the nose (mucus lining or membranes) after allergens are inhaled. Adjacent areas, such as the ears, sinuses, and throat can also be involved.

Cold and throat allergy symptoms overlap

It's often hard to tell, even for doctors, about cold and throat allergy symptoms. Colds are caused by hundreds of different viruses. Some of the effects are the classic symptoms of a cold, such as congestion and coughing.
Throat allergies are caused by an overactive immune system. For some reason, your body mistakes harmless substances, such as mold or pollen for germs and attacks them. Your body releases chemicals such as histamine, just as it does when fighting a cold. This can cause swelling in your nasal passages, a runny nose, coughing, and sneezing. Although there are some differences, cold and throat allergy symptoms overlap quite a bit. The most important difference is that colds don't last longer than 14 days.