Saturday, April 9, 2011

Sneezing and Itchy Eyes: Allergy Symptoms in Children

Spring is here and so are allergies. Parents often have a difficult time identifying allergies from illnesses like colds or sinus infections. The term "allergies" can have many connotations, including a runny nose and cough, hives, anaphylaxis, food allergies, asthma, and eczema to name a few.  In this post, when I use the term "allergies," I am referring to allergic rhinitis and its associate symptoms (unless otherwise specified).  Before continuing, I suggest you read about the common cold, as I will referrence this and it is the entity that parents often confuse with allergies.

My experience is that parents often falsely assume that cold symptoms are due to allergies. They often try an over-the-counter allergy medicine and are baffled as to why it is not helping. So how does the astute, yet anxious, parent tell the difference between a cold and allergies? Here are some things to consider:

Age: If your child is under a year old, his symptoms are likely not due to allergies. Allergies take time to develop and a child under a year old typically has not developed an immune system capable of having allergic rhinitis (stuffy or runny nose from allergies). Other allergic phenomena, such as eczema and food allergies can occur in young infants, but these typically do not result in a runny nose.

Family History: Allergies tend to run in families. Unfortunately, falsely attributing cold symptoms to allergies also runs in families.

The Atopic March: It is well known that children prone to allergies often have eczema as infants. As they get older they tend to develop allergic rhinitis and some will go on to develop asthma. This is called the atopic march--the progression from eczema to allergic rhinitis to asthma. So if your child has a history of eczema, there is a greater likelihood that his runny nose is due to allergies.

Abrupt Onset vs Chronic Symptoms:  In general if your child is fine on one day and sick the next, this is probably not allergies. Allergies tend to be more chronic. If a parent can tell me the day the symptoms started, I am less suspicious of allergies. If the parent says the symptoms have been going on for "a while," allergies moves up my list of possible causes. One caveat to this is children in daycare. Their noses are always snotty due to one viral infection (cold) after another.  If examined closely, parent of the daycare child will describe episodes of cold symptoms that typically go away after 10 to 14 days, followed by no symptoms for a few days or weeks, then another similar illness.  In other words, there is typically a period of no symptoms between discrete illnesses.

Fever: Allergies do not cause fever. Viral illnesses do. If your child's runny nose started with a fever, the current symptoms are very unlikely to be allergies.

Itchy Eyes and Nose: A major chemical in the production of allergy symptoms is histamine. Histamine causes itching. So if an itchy nose or itchy eyes are part of your child's symptoms, allergies are more likely to be the cause.

Seasonality:  Many of the common causes of allergies occur during specific times of the year, such as pollen from trees or grasses.  Other causes of allergies, such as dust (dust mites) are typically year round.  Pet allergies are typically present when the child is around a type of pet dander to which he is allergic.  This may be constant if the child is constantly exposed to the pet.  So a repetitive pattern of symptoms during a specific time of year, such as every spring, makes me more concerned for seasonal allergies. 

Physical Findings: There are often things your pediatrician can identify during the physical exam that support the diagnosis of allergies, such as the allergic salute.  The repetitive (remember chronic symptoms) rubbing of the nose (remember itching) leads to a crease across the bridge of the nose.

The allergic salute
Crease across the bridge of the nose.

Other common findings are Dennie-Morgan lines and allergic shiners.  Dennie-Morgan lines are creases found below the eyes and allergic shiners are the dark circle under the eyes.

In reality it is sometimes hard to decipher the role of allergies in a child's symptoms.  Sometimes I will prescribe an allergy medicine to see if it helps.  If it does, that supports the idea that the symptoms are an allergic phenomena. Why not just do allergy testing?  Allergy testing is invasive, requiring blood tests or skin testing. Most children are not big fans of this. Testing can also be expensive (a typical blood allergy panel can cost over $500).  Often the results do not change the management of the child.  For example, if we discover through testing that a child is allergic to a specific pollen, there is little that can be done for this other than take an allergy medicine.  In other words, you cannot cut down all the oak trees in the neighborhood.  I typically do not pursue allergy testing, unless I am suspicious that we can decrease the child's exposure to the offending allergen, such as get rid of the cat or take dust mite precautions within the household.  Another reason I will utilize testing is when the child's symptoms are not controlled with allergy medicines or when there are problems controlling asthma that is triggered by allergies.  In these situations, allergy shots become a viable alternative to helping the child's symptoms.  To do allergy shots, we have to know what specifically is causing the child's allergies, thus, testing is required.

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