Food Teleggy: Diagnosis Of Food Allergies
DIAGNOSIS OF FOOD ALLERGY:
Food allergies should be diagnosed by medical professionals trained in allergic disease management, such as allergists. The diagnosis process typically begins with the provider obtaining a detailed symptom history followed by a physical examination and, if allergy is suspected, further testing. Proper diagnosis is important to avoid unnecessary dietary restrictions, which may lead to inadequate nutrient intakes and/or undue psychosocial stress.
History:
A thorough food history is taken with details on foods eaten, food preparation, timing of onset of symptoms in relation to exposure, and symptom severity and duration.
Physical examination:
The physical examination looks for signs of atopic dermatitis, asthma and …show more content…
allergic rhinitis. The provider may also look at a child’s growth and development.
Allergy tests
The skin-prick test (SPT) is an inexpensive, rapid and safe method for diagnosing an IgE-mediated food allergy. A patch of skin is scratched multiple times and a small amount of allergen is placed on the skin. The size of the wheal (red, swollen area) is compared to a control patch (histamine); generally, a larger wheal indicates a likely food allergy though 50-60% of SPTs result in “false positives” (the test shows a positive result, however the individual is not actually allergic to the food being tested) (FARE, 2016)this is not always accurate (FARE, 2016). It is important to keep in mind that 50-60% of SPTs result in “false positives” (the test shows a positive result, however the individual is not actually allergic to the food being tested) (FARE, 2016), however a A positive SPT alongside a supportive history is generally diagnostic of food allergy. A negative SPT finding reliably predicts the absence of food allergy.
Serum-specific IgE blood testing can be completed if SPTs cannot be performed, however they are generally more expensive, take several days to obtain results, and are less sensitive.
Elimination diet
If a food allergy is suspected but the SPT and/or serum-specific IgE testing results are uncertain, the allergist may order an elimination diet, followed by a supervised oral food challenge. An elimination diet can determine whether a person actually reacts to the food. Suspected foods are avoided for 2-6 weeks until all symptoms clear. If symptoms do not clear and food allergy is still suspected, more restrictive elimination can be implemented. During this elimination period, a detailed food record should be kept to ensure suspected foods have not been accidentally consumed. Also during this time a vitamin or mineral supplementation may be necessary if certain food groups are not being consumed.
Once symptoms are completely cleared, an oral food challenge can be conducted in a doctor or allergist’s office.
Foods are reintroduced to the diet one at a time while the patient is carefully observed for the recurrence of symptoms; reactions are monitored in the food record. The initial challenge begins with a very small amount of the food. If no reaction occurs, the dose is increased gradually at each feeding until a response occurs or the amount of food offered is the same as a normal serving size. When a positive reaction is observed, the allergist may recommend that the food again be eliminated until symptoms abate and repeat the challenge to verify the reaction was caused by the food rather than a coincidental event.
During the food challenge, patients should be closely observed by a healthcare professional for extreme reactions. Emergency equipment should be available as severe anaphylactic reactions possibly leading to death can occur after a period of elimination.
There are food allergy tests available that have not been scientifically proven for efficacy and are not standardized (Begin, P). These are not recommended in food allergy diagnosis and include (Begin, P):
• Applied Kinesiology (muscle testing)
• Cytotoxicity
testing
• Electrodermal test (vega testing)
• Nambrudipad’s Allergy Elimination Technique (NAET) a.k.a. Natural Elimination of Allergy Treatment (NEAT)
• IgG/IgG4 testing
• Hair analysis
• Pulse testing
If any of the above tests were used to diagnose a patient with food allergy, it is recommended the individual is re-tested by an allergist.
Food allergies should be diagnosed by medical professionals trained in allergic disease management, such as allergists. The diagnosis process typically begins with the provider obtaining a detailed symptom history followed by a physical examination and, if allergy is suspected, further testing. Proper diagnosis is important to avoid unnecessary dietary restrictions, which may lead to inadequate nutrient intakes and/or undue psychosocial stress.
History:
A thorough food history is taken with details on foods eaten, food preparation, timing of onset of symptoms in relation to exposure, and symptom severity and duration.
Physical examination:
The physical examination looks for signs of atopic dermatitis, asthma and …show more content…
allergic rhinitis. The provider may also look at a child’s growth and development.
Allergy tests
The skin-prick test (SPT) is an inexpensive, rapid and safe method for diagnosing an IgE-mediated food allergy. A patch of skin is scratched multiple times and a small amount of allergen is placed on the skin. The size of the wheal (red, swollen area) is compared to a control patch (histamine); generally, a larger wheal indicates a likely food allergy though 50-60% of SPTs result in “false positives” (the test shows a positive result, however the individual is not actually allergic to the food being tested) (FARE, 2016)this is not always accurate (FARE, 2016). It is important to keep in mind that 50-60% of SPTs result in “false positives” (the test shows a positive result, however the individual is not actually allergic to the food being tested) (FARE, 2016), however a A positive SPT alongside a supportive history is generally diagnostic of food allergy. A negative SPT finding reliably predicts the absence of food allergy.
Serum-specific IgE blood testing can be completed if SPTs cannot be performed, however they are generally more expensive, take several days to obtain results, and are less sensitive.
Elimination diet
If a food allergy is suspected but the SPT and/or serum-specific IgE testing results are uncertain, the allergist may order an elimination diet, followed by a supervised oral food challenge. An elimination diet can determine whether a person actually reacts to the food. Suspected foods are avoided for 2-6 weeks until all symptoms clear. If symptoms do not clear and food allergy is still suspected, more restrictive elimination can be implemented. During this elimination period, a detailed food record should be kept to ensure suspected foods have not been accidentally consumed. Also during this time a vitamin or mineral supplementation may be necessary if certain food groups are not being consumed.
Once symptoms are completely cleared, an oral food challenge can be conducted in a doctor or allergist’s office.
Foods are reintroduced to the diet one at a time while the patient is carefully observed for the recurrence of symptoms; reactions are monitored in the food record. The initial challenge begins with a very small amount of the food. If no reaction occurs, the dose is increased gradually at each feeding until a response occurs or the amount of food offered is the same as a normal serving size. When a positive reaction is observed, the allergist may recommend that the food again be eliminated until symptoms abate and repeat the challenge to verify the reaction was caused by the food rather than a coincidental event.
During the food challenge, patients should be closely observed by a healthcare professional for extreme reactions. Emergency equipment should be available as severe anaphylactic reactions possibly leading to death can occur after a period of elimination.
There are food allergy tests available that have not been scientifically proven for efficacy and are not standardized (Begin, P). These are not recommended in food allergy diagnosis and include (Begin, P):
• Applied Kinesiology (muscle testing)
• Cytotoxicity
testing
• Electrodermal test (vega testing)
• Nambrudipad’s Allergy Elimination Technique (NAET) a.k.a. Natural Elimination of Allergy Treatment (NEAT)
• IgG/IgG4 testing
• Hair analysis
• Pulse testing
If any of the above tests were used to diagnose a patient with food allergy, it is recommended the individual is re-tested by an allergist.