This word is commonly used to describe anything that causes watery eyes, runny noses, itching, and sneezing. More specifically allergy refers to a hypersensitivity reaction to something (ie dog, cat, trees, dust mites, wheat) with protein structure. It is mediated by immunoglobulin E. The reaction is unnecessary as these are not infectious agents such as viruses or bacteria. Unfortunately, the reaction causes damage to the mucosal surface of the nose which can lead to further problems such as nasal obstruction and chronic sinusitis. It also makes one more susceptible to viral infections such as the common cold leading to acute sinusitis. Treatment includes avoidance, antihistamines–oral and topical nasal, nasal steroid sprays, and immunotherapy. Immunotherapy includes allergy shots (SCIT) or drops (SLIT).
Patients who believe they have “allergies” but do not improve with antihistamines such as allegra or zyrtec, may suffer from nonallergic rhinitis. Nonallergic irritants include smoke, perfumes, dust, ozone, and many others. Topical nasal steroid and nasal antihistamines are effective treatments for allergic and nonallergic rhinitis. Patients who have an incomplete response to these medications often have chronic sinusitis. These patients need to see a sinus specialist for further workup and treatment.