Many adolescents are afflicted with allergies, and now scientists understand why some teens have allergies. Our immune system is designed to recognize and react against foreign substances. For example, there are immune defenses against bacteria, viruses and fungi; as a result, our body fights against infections caused by these agents. The body also recognizes non-infectious foreign particles. If the body over responds to a non-infectious foreign particle, then an allergic reaction may occur.
The body produces antibodies that help to protect against infection. These are termed IgG and IgM immunoglobulins. In the case of an allergic response, the body produces the IgE immunoglobulin. Common particles or allergens that can cause a teen to develop an allergic reaction include medications, foods, animal danders, insect venoms, plant pollens, molds, dust mites and chemicals.
If a teen has an allergic reaction, the body overproduces IgE antibody. These antibodies attach to mast cells that are located in the lungs, skin and mucous membranes. After the IgE antibody is attached to the mast cell, certain chemical transmitters including histamine are released. Histamine will cause the skin to turn red and itch. As a result, the eyes in an allergic individual could be red and itchy. In the nose, histamine will cause itchiness, congestion and sneezing.
Allergies from the environment may occur seasonally as the case of springtime allergies and hay fever or ragweed allergy that occur in the late summer and fall. Depending on the climate, trees begin to release pollen in late March to April in most of the United States. Grasses may cause allergy from mid May to late June. Ragweed affects about seventy-five percent of allergy patients in the United States, and the plant is fairly ubiquitous. A ragweed plant can release up to one million pollen grains each day; usually ragweed causes allergic problems from late August until the first frost in the northern regions of the United States.
Year round or perennial allergies can also produce symptoms in adolescents throughout the year. These allergens are usually in the house, and they include danders from animals, molds, house mites, or house dust.
Who is likely to develop allergies?
Depending on the study, from four percent to forty percent of adolescents may have symptoms of allergies. The following are risk factors for allergies:
Although allergies may develop in any adolescent, if one parent has allergies, then there is a fifty percent chance the teen will have allergies; if both parents have allergic symptoms then the chance the adolescent will have allergies approaches seventy-five percent.
Childhood allergies may predict allergies as an adolescent. If a child has eczema, there is a higher risk for allergies during adolescence.
There is some thought that the season when one is born might affect the risk for allergies and this is based on levels of IgE. According to this theory, children born in the fall months have a higher risk of allergy compared to those born in summer months.
There is some thought that healthier conditions may predispose adolescents to allergies. This is based on some studies that report an association between a western life style and higher increases in allergies.
What are the symptoms of allergies?
The classic symptoms of allergies include runny or congested nose, sneezing, itchiness in the nose, throat, eyes or roof of the mouth and bloodshot eyes. Allergic teens also complain about fatigue, headache, reduced sense of smell, postnasal drip and plugged ears. Some teens develop allergic shiners, which are dark circles under the eyes. These are probably related to venous congestion due to the allergies. Other teens have an allergic “salute” which is a crease on the nose. This occurs when the teen repeatedly pushes his or her nose upward with the palm of the hand. They may also twitch the nose due to the itch or in an effort to clear congestion. Fever and body aches are not associated with allergies. Thick yellow or green nasal discharge also is not seen in allergies. This may represent a secondary infection.
How are allergies evaluated?
A good history and physical examination is needed to determine if a teen has allergies. The history will attempt to determine the family history for allergies, any triggers, pets in the house, when the symptoms begin and if the symptoms are year round. The clinician will evaluate on physical examination, the adolescent’s eyes, ears, nose, throat and chest.
Certain laboratory tests may also be performed to determine the specific allergies. A blood examination called RAST, the RadioAlergoSorben Test, is used to determine the level of IgE to certain allergens such as peanuts or milk. RAST is expensive and not necessarily accurate. Skin tests may be performed on teens. The specialist can inject under the skin a drop of the specific allergen, such as ragweed, and observe the skin for twenty minutes. If there is an allergic reaction, then a red, swollen hive usually appears quickly. For most mild seasonal allergies, skin testing is probably unnecessary.
How are allergies treated?
Avoidance, removal, decongestants, antihistamines, nasal steroids or allergy injections may help to treat allergies. While it is difficult to avoid ragweed when it is in season, staying in an air-conditioned house may help to avoid the ragweed allergen. Since allergens cause reaction by landing on the nasal mucous membranes, then a simple nasal wash may effectively remove the allergens. These washes are available in pharmacies.
Drug therapy is the most common treatment for allergies. Since histamine is released during the allergic reaction, then an antihistamine medication should bring relief of the symptoms to the adolescent. Antihistamines should produce relief of runny nose, itchy eyes and sneezing. Older antihistamines including diphenhydramine (Benadryl) or chlorpheniramine (Chlor-Trimeton) are usually effective. However, since these medications pass through the blood-brain barrier, they frequently cause drowsiness especially when the teen first begins the medication. They also need to be taken up to four times each day. The newer antihistamines, the so-called second generation drugs, include cetirizine (Zyrtec), loratadine (Claritin) and fexofenadine (Allegra). These do not pass through the blood-brain barrier; so most teens do not become drowsy from the medication. Obviously this is important for teens who need to study, work or drive. Cetirizine and loratadine need to be taken only once daily. Itchy eyes may be treated with eye drops that include antihistamines such as olopatadine (Patanol). Nasal decongestants may also be used to dry the nasal mucous membranes. These include nose drops with oxymetazole such as Afrin or oral medications such as pseudoephedrine (Sudafed). Several of the oral second generation antihistamines were made over-the-counter around 2004.
Steroids sprayed onto the nasal mucous membranes have been shown to be safe and effective for allergies. They have been shown to diminish mucous production and inflammation. Products including beclomethasone (Beconase), fluticasone (Flonase) and mometasone furoate (Nasonex) have been helpful for teens with nasal allergies.
Allergy injections or immunotherapy may also be effective in adolescents with allergies. The theory is that a teen who receives increasing doses by injection of a specific allergen to which he or she is allergic will lose sensitivity to that allergen. The advantage to allergy shots is that the allergist can target specific allergens for treatment. However, the shots usually need to be given over a period of months, often as frequently as twice weekly visits to the physician’s office, and it may take six months for the teen to achieve relief from allergic symptoms. Allergy shots may be given to a teen with severe allergies who has not responded to medication. Life threatening allergies such as bee venom hypersensitivity may also be treated with allergy injections.
How are allergies prevented?
Interestingly, one study showed that exposure to cats and dogs in the child’s first year may prevent later development of allergies. Air cleaners, air conditioners that have filters and vacuum cleaners with HEPA (High Efficiency Particulate Arresting) filters may remove particles and small allergens from indoor air. Central vacuum systems deliver dust and dirt to a central repository typically in a basement or garage. Semi permeable mattress and pillow coverings may help to reduce dust mites. Curtains may contain allergens, so one could replace these with shades. And be certain to clean the canopy on a canopy bed, or forgo the canopy. Hardwood floors without carpets or rugs are ideal since allergens or dust mites may lodge in fabrics.
Cockroach allergies have been documented in teens. An exterminator should eliminate the roaches. Overuse of humidifiers or vaporizers may cause mold or increase mite populations. Humidity levels should not exceed forty percent in the house during the cold seasons. Humidifiers and vaporizers should be cleaned with vinegar and water ideally on a daily basis. Mold can be controlled in a humid basement by utilizing a dehumidifier.
Outdoor exposure should be avoided in high allergen periods. For example, if a teen has ragweed allergy, then camping in September should probably be avoided unless his or her symptoms are controlled with medications. If a teen has allergy to grass, then he or she should not be mowing the lawn.
Related topics:
Anti-inflammatory drugs, eye problems, genetic disease, nasal polyps
