clinical presentation,diagnosis,treatment of food allergy allergy&immunology unit,ain shams faculty of medicine Egypt prof.fawzia abo ali

1. Fawzya abo ali
Prof. of int.medicine & allergy
Ain shams faculty of medicine

2. Emily’s Story
Emily Vonder Meulen
Born 1992
 Eczema immediately
present on much of her
body
 Peanut Allergy at 2 years
old
 Diagnosed with Asthma
around 10 years old
www.foodallergyangel.com

3. April 2006, one month from 8th
grade graduation and from her 14th
birthday
she went shopping for graduation dress
 Emily was at a Cincinnati restaurant
where she ordered a chicken sandwich.
 Catrina,the mother said ,we ordered
around 2:50and were done eating about
3:10 But, about 10 minutes after she
finished it, she struggled to breathe.
I called 911 at 3:26 but it was too
late.
The doctor’s pronounced her dead at
4:20 from anaphylaxis.

4. What is food allergy?What is food allergy?
 Food allergy is one of the adverse
reactions to food ,defined as: an
abnormal response to food, mediated
via the immune system.

6.  Epidemiology:
 Approximately 8% of children and 1-6% of adults
suffer from true food allergies.

7. Pathophysiology
 GI tract forms a barrier to outside environment
 GALT inhibits responses to non-dangerous antigens
while mounting responses to pathogens
 Intact food antigens may penetrate the GI tract but
not cause clinical symptoms
 Develop in genetically predisposed individuals when
oral tolerance fails
 Increased intestinal permeability to
 macromolecules ;
 – Viral gastroenteritis,
 premature birth, cystic fibrosis
 – Leaky gut syndrome (LGS)

8. Foundation for Integrated Medicine
Immunologic Mechanisms of
Food allergy
 Type I (IgE mediated, TH2 promoted)
 Type II (IgG and complement mediated,
cytotoxic, TH1 promoted)
 Type III (IgG immune complex mediated,
TH1 promoted)
 Type IV (cell-mediated, TH1 promoted)

11. IgE Mediated food reactions
Cutaneous
 Urticaria &Angioedema
 Morbilliform rashes,Flushing
Gastrointestinal
 oral allergy syndrome
 Vomiting and diarrhea
Respiratory
 Upper
 Ocular pruritus and tearing
 Lower
 Bronchospasm/wheezing
Generalized
 Anaphylactic shock

13. Non-IgE Mediated
Type II: Antibody dependent cytotoxicity
 Specific antibody binds to a surface tissue
antigen and
 Milk-induced thrombocytopenia
Type III: Antigen-antibody complex mediated
 Can be found in sera of normal patients
&in patients with food hypersensitivity
 Little support for causing disease

14. Type IV: Cell-mediated hypersensitivity
Mediated by sensitized CD4+ T lymphocytes
which process antigens and release cytokines .
 the reaction mediated through macrophages
begins in hrs but reaching a peak in 2 to 3 days.

15. Sympt. Of delayed food allergy
Cutaneous
 Contact dermatitis,eczema
 Dermatitis herpetiformis
Gastrointestinal
 Food protein-induced enterocolitis
 Food protein-induced proctocolitis
 Food protein-induced enteropathy
 Celiac disease
Respiratory
 (Heiner syndrome)
 asthma

16. Mixed IgE and Cell Mediated
 Atopic dermatitis
 Allergic eosinophilic esophagitis
 Allergic eosinophilic gastroenteritis
 Asthma

17. Soy
Cow’s milk Peanut Tree nuts
Fish Shellfish
Egg white
Wheat

18. Food Allergen Proteins
 Cow milk β-lactoglobulin
 Egg yolk Lipoprotein
 Peanuts Peanut I + others
 Soybeans Glycinin + others
 Codfish Allergen M
 Green peasAlbumin
 Rice Glutelin/globulins
 Tomatoes Glycoproteins

19. Fatal Food-Induced Anaphylaxis
Accounts for 1/3 of all anaphylaxis seen in
emergency rooms
 Symptoms:generalized
 Dx by history and demonstration
 of food specific IgE
 Most were adolescents or young adults
 History of prior reaction to implicated food
 Only 10% had epinephrine available
 Peanuts and tree nuts for majority (94%)

20. Exercise-Induced Anaphylaxis (EIA)
 Rare form occurring when patient
exercises 2-4 hrs after ingestion of
specific food
 Without exercise, food no problem
 Most common in women prior to
menstruation
 Dx based on history and evidence of
specific IgE
 Common offenders: wheat, shellfish,
fish, fruits, milk

21. Celiac Disease

22. Food diary
(DBFC)
SPT
Patch
Diagnosis of Food Allergy

24. Skin prick testing

27. Treatment of food allergy
 Treat the reaction
 Avoid the food:The only proven treatment
for a food allergy is to avoid the food.
 Read food labels
 OIT and SLIT show great promise, and a
widespread treatment for food allergy may
be within reach.
 probiotics