Bruce Prenner, MD
The incidence of allergies in children has increased significantly in the last two decades. There are now more children with asthma, hay fever, and eczema than ever before. Closely following this increased prevalence of allergies is the rise in asthma, which has become the number one diagnosis for child hospital admissions. In my own practice in recent years, I have seen a steady stream of children as young as six months presenting with an allergic rash (eczema) as well as asthma and chronic nasal irritation (chronic rhinitis). Parents tell me that their children have runny noses, itchy and watery eyes, coughing and wheezing, without any evidence of viral infection. Many are convinced that their child's exposure to flowers, grass, weeds, and pets is the culprit.
General Information on Allergies
Allergies can develop in the first few months of life, evident as nasal congestion, cough, rash, or diarrhea following the ingestion of certain foods. Allergies affect all races and have been found in all parts of the world. Allergy is the term used to describe our immunologic sensitivity to an allergen (any substance that causes an allergic reaction). This sensitization may occur by inhaling airborne allergens or eating food that contains allergens. The consequence of allergens entering into our body involves the release of chemical messengers that bring about the well-known symptoms of allergy listed below:
-itchy or stuffy nose
-watery nasal discharge
-eye tearing and redness
And less frequently:
-palatal (roof of the mouth) itch
-bronchial asthma symptoms, such as wheezing.
If your child develops allergies, the cause will have been a combination of the genes he or she inherited from you as well as their environmental exposures. As parents, if one of you has a history of allergies, then each child will have about a 25% chance of developing allergies. If both of you have allergies, the risk increases to about 50%.
Genetic factors have also been intensively researched in recent years and what has emerged is that the genetics of allergy are quite complex, involving interactions between our environment and inherited tendencies. The exact genes that account for our allergies have not been fully identified.
In contrast to the genetic influences, the influence of environmental exposure has been well-established. The presence of pets, such as cats and dogs, in homes clearly affects whether your susceptible child will be reactive to these allergens. It is also true, however, that children can still become sensitized to allergens that have been eliminated from the home environment. Exposure to allergens, such as animal dander, is hard to avoid in school or day care and in outdoor areas as these allergens may be on the coats and clothing of children from homes with pets.
There are also currently many theories as to other possible causes for allergy in children (and adults):
- Exposure to particulate matter released from the burning of diesel fuel, mainly from trucks, triggers the allergic response. This theory has been proved in the laboratory, where certain cells exposed to diesel particulate matter show signs of an allergic response.
- Air pollution has been cited as a stimulus that can provoke the development of childhood asthma. Evidence for this is that high ozone and sulfur dioxide levels often coincide with peak asthma exacerbations or flare-ups.
- Tiny airborne mold spores (specifically, the species Alternaria), which cannot be seen, have recently been associated with epidemics of asthma in certain cities in children and adults.
- Dust mites and cockroaches appear to be major sensitization agents in our inner cities.
- Cockroaches have proven to be very difficult to eliminate; dust mites are only somewhat easier.
- This abundance of possible causes may seem daunting, but studies have nevertheless shown that certain measures like maintaining a pet-free home, breastfeeding, or soy formula feeding for at least six months or more, along with the late introduction of solid foods (greater than six months of age) can delay the onset of allergic symptoms in susceptible children.
What Is a Parent to Do?
The goal shared by both physicians and parents alike in treating childhood asthma and allergies should be to minimize the side effects of medications while maximizing the chance of our children to lead normal daily lives. Clearly identifying allergens that your children are sensitive to through allergy skin testing or using a specific blood test (called a RAST test), can be extremely helpful to you in implementing the following avoidance and control measures.
Avoidance and Control Measures for Children with Allergies
- Removing carpet, encasing bedding with breathable covers, hot laundering of linens, and keeping windows closed at night and in the early morning hours can minimize your children's allergic burden and exposure. Also decreasing the prevalence of dust mites in the bedrooms of your children who are allergic to dust mites and are asthmatic can have a major improvement in their lung function and result in a reduced need for concomitant medications to treat their flare-ups.
- Avoidance of allergy triggers, which may include such irritants and odors as perfume, tobacco smoke, and colognes, will also help your allergic children. Unfortunately, since viruses, particularly rhinoviruses (the cause of the common cold), are the most common stimulant of childhood asthma, and there are as yet no specific practical means available to deal with inactivating this virus or decreasing its penetration in the upper respiratory tract, we are powerless to prevent virus exposure. However, vaccination with flu vaccine and appropriate new agents, as they are released and shown to be safe for children, will be very worthwhile.
- Weather changes can be extremely provocative of asthmatic symptoms as are other seasonal factors, such as presence of pollen. Unfortunately, they are difficult to avoid.
Scheduling outdoor playtime or exercise at non-peak pollen periods, such as afternoons or early evening, can be effective.
- Having your child wear a mask when helping with gardening, vacuuming, or dusting can be very helpful.
In addition, the recent availability of newer therapeutic agents for use in children has been extremely useful in managing rhinitis as well as asthma:
- Non-sedating antihistamines available in liquid form and rapidly dissolving tablet form can be very beneficial.
- Sodium cromolyn, which is an over the counter product, used as a nasal spray to prevent nasal allergy symptoms has also been shown to be effective.
- Inhaled nasal corticosteroids have been also shown to be quite effective in ameliorating allergic inflammation.
- A leukotriene antagonist, a new class of drugs, has been approved for the treatment of childhood asthma and is available in a chewable form. Such agents can decrease asthma symptoms and also improve the quality of life.
In summary, allergies are partly due to genetic tendencies of a child born to parents or relatives with allergies to react to normally harmless substances in the environment (allergens). Common allergens include pollen grains, dust mites, house dust, airborne mold particles and animal dander. Long-term complications of allergy in children include sinus problems (sinusitis) and recurrent ear problems such as serious and chronic fluid in the middle ear (otitis media). Those conditions may require antibiotics as well as, in the care of ears, the placement of ear tubes for ventilation.
It is my opinion that the biggest challenge we face together as physicians and parents is the lack of participation of the allergy specialist in the care of our allergic and asthmatic children. Primary care providers, such as family physicians and pediatricians, need to be encouraged involve the allergist more frequently in the care of their patients and to trust the allergist as an equal partner in the delivery of appropriate health care. Meeting this challenge will be extremely important to both the patient and the parent.