Spring allergies are the result of pollen from trees, which can start pollinating anytime from January to April, depending on the climate and location. Trees that are known to cause severe allergies include oak, olive, elm, birch, ash, hickory, poplar, sycamore, maple, cypress and walnut. Grass pollen is typically the main cause of late spring and early summer allergies. Grass pollen is highest at these times, although grass may cause allergies through much of the year if someone is mowing the lawn or lying in the grass. Contact with grass can result in itching and hives in people who are allergic to grass pollen, this is called contact urticaria. Grasses can be divided into two major classes, northern and southern grasses. Northern grasses are common in colder climates, and include timothy, rye, orchard, sweet vernal, red top and blue grasses. Southern grasses are present in warmer climates, with Bermuda grass being the major grass in this category. Weed pollen is the main cause of seasonal allergy in the late summer and early fall. Depending on the area of North America, these weeds include ragweed, sagebrush, pigweed, tumbleweed (Russian thistle) and cocklebur. In New England, ragweed is a very common offender.
Avoidance is always a better option than treatment - however, it is often difficult or impossible to avoid these pollens (unlike allergies to pet dander and dust mites, where avoidance is at least a possibility!). Here are some tips to minimize pollen exposure:
When allergy strikes, you have many options. If you have itchy, watery eyes, runny nose, sneezing and scratchy throat, you are probably best served by an oral antihistamine. Most are over-the-counter (you don't need a prescription to purchase them). One of the best is chlorpheniramine (sold as a generic as well as under the brandname Chlor-Trimeton). It comes in an immediate-release short-acting pill (taken 4 mg every 4 to 6 hours) or as an extended-release pill (taken 8-12 mg twice per day). Loratadine (Claritin or Alavert) and cetirizine (Zyrtec) are now over-the-counter, and may cause less drowsiness than older antihistamines.
When nasal congestion and runny nose are the dominant allergy symptom, the best treatment is a nasal steroid. Fluticasone (sold as Flonase) is used only once per day (1-2 puffs in each nostril), and is quite effective in reducing nasal symptoms provided it is used for a least a few days in a row. It works by decreasing inflammation in the nose, and does not work right away. For immediate relief of nasal congestion, oral medicines like pseudoephedrine (Sudafed - 30-60 mg every 4-6 hours) or phenylephrine (Sudafed PE - 10 mg every 4 hours) can be taken, though these will not help with allergy. Another option is Afrin nasal spray, but this should never be used for more than a few days, as rebound nasal congestion is a major problem with prolonged use.
When itchy/watery eyes are the major symptom, using a simple eye decongestant (like Visine Allergy Relief, Naphcon-A, or Opcon-A) may help. Another option is Zaditor eye drops - this is a combination antihistamine and mast cell stabilizer. What this means is that it provides immediate relief (the antihistamine) as well as tries to prevent further release of the mediators of allergy (the things your body releases in response to the pollens). This is now available over-the-counter for under $20.