What are spring and summer allergies?
Seasonal allergies are allergic responses of your respiratory system to breathing in pollens that are given off by trees, grasses and weeds. Pollens are like tiny microscopic balloons that float great distances on wind currents. Trees give off pollen each year from March into June. At other times of the year there is nothing about the tree that will bother you. Grasses start to pollinate heavily in early June and depending on the weather, continue into the summer. Weeds give off pollen generally in the fall. Another category of allergy that is important in the summer and fall is mold allergy. Various kinds of mold that grow on decaying vegetable matter give off spores that float in the air like pollen.
What causes allergies?
Allergies are a very complex immune reaction to proteins that are given off by pollens and mold spores that stick to the lining of your eyes, nose and lungs. Inflammation results and causes the various symptoms of allergy. One important characteristic of this immune reaction is the presence of a particular kind of antibody (called IgE) that binds to the surface of certain cells (mast cells) in your respiratory lining. When exposed to an allergen this antibody causes a release of histamine and a host of other substances from mast cells causing the inflammation. IgE antibody is useful to protect the body against certain parasitic infections, but its presence in allergies could be viewed as your immune system going awry and reacting to harmless things. Some degree of allergy occurs in as much as 15 to 20 percent of the population, especially in young adults. The tendency to have allergies has a strong genetic component, so allergies tend to run in families. Allergies are more common in developed countries; this has given rise to the "hygiene hypothesis" which put crudely states that too much cleanliness and protection against germs causes the immune system to misdirect itself and react to harmless things.
What are the symptoms of allergies?
The common symptoms of allergies are
- Eye itching, redness and running
- Nasal congestion with bouts of sneezing and nose running
- Throat irritation and itching
- Cough, wheezing and shortness of breath.
It is sometimes difficult to distinguish the common cold (caused by a virus) from allergies because a lot of the symptoms are shared. A cold, however, usually lasts for only a week; allergies often go on for much longer. A cold may also be associated with a fever. Uncomplicated allergies are not associated with a fever. Allergies come on at a predictable time from year to year; a cold is much more random.
How are allergies diagnosed?
The cornerstone for the diagnosis of allergies is the detection of IgE antibody directed against specific pollens or molds. Skin testing is the most common and rapid way to diagnose allergies. This is done by applying extracts of pollens or molds to the skin with a tiny prick or abrasion and if you are allergic, an itchy swelling or “wheal” results within 15 minutes. Blood tests can also be done (the RAST test). This measures IgE antibody to specific allergens in the blood. The skin test is a little more sensitive and provides more information more quickly.
How are allergies treated?
Antihistamines are the major over-the-counter treatment for allergies. A large number of products are available, but the newer non-sedating products are generally preferable.These include loratadine (Claritin) or cetirizine (Zyrtec). Many antihistamine preparations are combined with pseudoephedrine for its decongestant effect although for some, this has a bothersome stimulant side-effect. Over the counter vasoconstrictor nasal sprays (such as Afrin) provide temporary relief but can induce dependency if used for more than 3-4 days. Nasal saline sprays can be very useful, and when used frequently, can rinse out pollen that is trapped in the nose.
When should a physician be consulted?
In many cases the symptoms are quite mild and are easily treated with over-the-counter medication. Generally speaking, nasal congestion is more difficult to treat than a runny nose and sneezing. When the symptoms are severe enough to interfere with quality of life and do not respond to simple over-the-counter medication, a physician should be consulted. These more severe symptoms include:
- Sleep interference at night with daytime fatigue
- Symptoms of sinusitis that can complicate allergies such as pain above or below the eyes and post nasal drainage
- Symptoms of asthma including cough, wheezing or shortness of breath.
What additional treatments can a physician prescribe if over-the-counter medication does not work?
Nasal cortisone sprays are highly effective if used regularly for a period of time. A short course of cortisone pills can get you through a severe crisis when all else fails. Allergy shots or desensitization can be effective, but this is a long-term treatment that requires regular shots for a number of years. Desensitization is very helpful for some when other treatments are not effective. Asthma, if it occurs, must be treated promptly by your physician.
Is there a cure for allergies?
Unfortunately there is not a simple cure yet. Most of our treatments reduce the severity of the allergic reactions.
Can complications occur with allergies?
The major complications of summer allergies consist of sinus and ear infections. The cause is swelling in the nasal membranes that impede drainage from the sinuses and ears. Persistent pain in the sinus area or ears is a major symptom of this. Asthma is a much more serious form of allergy and requires prompt attention if it occurs.
Are you suffering from allergy symptoms or know a patient who is? Contact the Division of Allergy at 617-636-5333 or visit the Division webpage.