Food Allergies in Infants and Children Shana Spector

Food Allergies in the U.S. More than 6 million Americans suffer from food allergies 3 million specifically allergic to peanuts, walnuts, and pecans Other common food allergies: milk, fish, shellfish, wheat and soy

What Causes Allergic Reactions? Overactive immune system Body believes a substance is harmful Body wants to protect itself by fighting that substance off Immune system releases chemicals and histamine, triggering the reaction

IgE Mediated Allergy Disorder Cause acute onset of symptoms after digestion Affect skin, respiratory tract, gastrointestinal tract and cardiovascular system

IgE Mediated Allergy Disorder IgE antibodies are cells that are released from specialized B cells during contact with allergen IgE antibodies attach to IgE receptors on mast cells

IgE Mediated Allergy Disorder If the allergen is again presented in the body, it binds to surface of mast cell, triggering release of histamine and other chemicals Picture and animation

Types of IgE Mediated Disorders Type 1 Hypersensitivity: most common disorder Symptoms include hives, swelling of face, itching, vomiting, diarrhea, coughing, wheezing and decrease in blood pressure

Types IgE Disorders Oral Allergy Syndrome Caused by allergies to fruits and veggies Itching swelling of lips, tongue, palate and throat

Types IgE Disorders Respiratory Hypersensitivity Reaction Effects respiratory tract Causes runny nose, nasal congestion, wheezing and coughing

Types IgE Disorders Airborne Food Allergy Reaction Transpires from smelling an allergen through cooking Causes nasal congestion, inflammation of the eyes and hives

Types IgE Disorders Food-Associated Exercise-Induced Anaphylaxis Occurs when allergic person exercises 2-4 hours after eating certain foods No reaction without exercise More common in females (esp. teenagers)

Other Food Disorders Subacute or chronic Usually affect gastrointestinal tract Mediated by T cells Mainly found in infants and children Usually caused by hypersensitivity to cow’s milk or soy

Symptoms of Food Allergies Hives are most common Other symptoms: tingling in mouth, swelling in the tongue and throat, difficulty breathing, abdominal cramps, vomiting, diarrhea, and eczema

Anaphylaxis Serious allergic reaction occurring within a few minutes to two hours after contact with allergen Acute and potentially fatal Causes 300,000 hospital visits and 150-200 deaths per year

Infants, Children and Food Allergies 6-8% of children develop food allergies within the first three years of life 90% of food allergies in kids involve cow’s milk, egg, peanut, wheat, soy, tree nuts, or fish

Infants, Children and Food Allergies Most children outgrow their allergies to milk, egg, wheat and soy by age 3-5 Only 20% of infants with peanut allergy will eventually tolerate peanuts

Problems Associated with Food Allergies in Children Poor nutrient intake Constipation Eczema Potential death

Food Allergies Linked to Poor Growth Increased risk for poor nutrient intake Parents may eliminate too many foods from child’s diet or neglect to supplement In severe cases, children can develop failure to thrive

Studies Showing Poor Growth Children with one or more food allergies more likely to be under 25th percentile height for age than healthy children Subjects with 2 or more food allergies significantly shorter than children with 1 Children with specific allergy to cow milk showed lower height for age than healthy children

What to do if Child has Food Allergies Consult with an allergist and dietician Use growth charts often to assess child’s growth

Food Allergies and Constipation Recent studies have linked infantile constipation to cow’s milk allergy Study shows infants switching to soy milk from cow milk alleviates constipation Study shows 5 year olds eliminating milk protein from diet and no longer suffering from constipation

Food Allergies and Atopic Dermatitis Atopic dermatitis: skin condition associated with food allergies in infants and children Atopy: refers to a tendency for excess inflammation in the skin, linings of the nose, and lungs Eczema usually runs in families

Food Allergies and Eczema 10% of infants suffer from eczema Skin becomes infected, with itchy rashes on face and scalp

Food Allergies and Eczema Study suggests that introducing solid food later in life will decrease prevalence of eczema Low-birth weight significantly correlated with a lower risk for food allergies and atopic dermitis

Potentially Deadly Reactions Most severe reactions in children: peanuts and other tree nuts Many are accidental: hidden nuts in brownies and cookies, peanut oil, etc. Symptoms progress with maturity Skin reaction during infancy to respiratory and gastrointestinal reactions later

Maternal and Familial Influence on Food Allergies Food allergies and atopy run in families 20% of children with eczema are the only one in family with problem

Maternal Influence and Possible Prevention Prevalence of peanut allergy is rising Pregnant women advised to eliminate peanuts from diet Allergy to peanuts may be preventable

Breastfeeding Mothers Breastfeeding may prevent food allergies and atopic dermatitis Can pass peanut allergy through breastfeeding It is recommended for mom to eliminate peanuts from diet while breastfeeding

Prevention of Cow’s Milk Allergy Hydrolysated formula Extensive or partially Only given to babies at high risk for atopic disease due to family history

Prevention of Cow’s Milk Allergy Babies given eHF combined with breast milk and no solid food until after 6 months of age Prevalence of food allergy and atopic dermatitis significantly reduced Babies given eHF or pHF: atopic disease greatly reduced in those given eHF

Diagnosis of Food Allergy What happens in the case of a mild reaction? What happens in the case of a severe reaction?

Tests and Procedures to Determine Food Allergy Skin Prick Test Identifies food specific IgE antibodies Test is either negative or positive

Tests and Procedures to Determine Food Allergy Radioallergosorbent Test (RAST) Done if test positive on SPT RAST is a blood test to determine food specific IgE RAST and SPT detect sensitization, but sensitization can occur without reaction

Elimination Diet Determines if given food is causing allergic reaction Food thought to be causing symptoms removed from diet Infants: change of formula or diet for breastfeeding mother Lasts 1-6 weeks

Food Challenge Also determines if specific food causes allergic reaction Performed under certain circumstances: 1)When several foods are under consideration, 2)IgE tests positive for several foods, and 3)elimination diet caused symptoms to end

Relevance to Parents Valuable for new parents and those thinking about reproducing May be able to prevent certain food allergies Be aware: unusual symptoms of child may be caused by food allergy Education is Key: inform teachers, babysitters, and any caretaker of child in order to prevent severe reactions