Histamine produces hives, watery eyes, sneezing, and itching. The most common symptom of seasonal allergies is allergic rhinitis, otherwise known as hay fever. Symptoms of allergic rhinitis closely mimic those of the common cold. But there are differences. A cold runs its course in 7 to 10 days.
Allergic rhinitis can drag on for weeks or months.
With a cold, nasal discharge may be thick and yellow. In allergies, it is generally thin and clear. An allergy is often accompanied by eye, skin or mouth itchiness and can often be traced to a specific trigger. The first step in handling chronic allergies is a visit to an allergist. The doctor will begin by taking a detailed medical history.