Oral allergy syndrome Flashcards
What is the pollen cross reactive components in peanut
Ara H5 and Ara H8
Hazelnut pollen cross reactive components
Cor a 1 and Cor a 2
Soybean pollen cross reactive components
Gly m4 and Gly m3
Wheat pollen cross reactive component
Tri a 12
Pollen NON-cross reactive components in peanut
Ara h2 and Ara h6
Pollen non-cross reactive components in hazelnut
Cor a 9 and Cor a 11
Pollen non cross reactive components in soybean
Gly m5 and Gly m6
gly 3 and 4 are betv1 homologues ie cause OAS
Pollen non cross reactive components in wheat
Tri a 19 (w-5 gliadin)
List your differential for adverse food reaction
Immune mediated
- Ige mediated
- Non ige mediated (FPIES)
- mixed ige and non IgE mediated (eosinophilic gastroenteritis)
- cell mediated (allergic contact dermatitis)
Non Immune mediated (intolerances)
- Metabolic (lactose intolerance)
- Pharmalogic (caffiene)
- Toxic (Scromboid)
- Idiopathic (sulfites)
Immunological changes that occur in SCIT
- Decrease in specific IgE
- Increased in specific IgG4
- Increased regulatory T cells with increased IL-10 and IGF beta production
- Shift away from TH2 producing cytokines (decreased IL4/5)
- Decreased mast cells, eosinophils and basophil activation
5 things that make food a good antigen
- heat stable
- acid stable
- abundant food source
- linear epitopes
- glycosylation
- high number of disulphide bonds
- Interaction with lipids
What is celery- mugwort syndrome?
Allergic to celery and react to other Apiaceae family plants: carrot, caraway, parsley, fennel, coriander, and aniseed), as well as to paprika, pepper, mango, garlic, leek, and onion may be seen
The pollen is mugwort
What is mugwort- mustard syndrome
If you are sensitized to mugwort, you can develop an allergy to mustard
10% rate of anaphylaxis to mustard
All are sensitized to Brassicaceae family (cauliflower, cabbage, broccoli), with 40% having clinical reactions
Name 3 plant proteins families
- PR-10 (mainly involved in OAS)
- Profilin (ie. Betv2)
- Lipid transfer proteins
Reasons to give EpiPen in OAS:
- Systemic symptoms
- Peanut, tree nut, mustard, ?peach (more in mediterranean) objectively established
- Oropharyngeal reaction to cooked food
- SPT positive to commercial extract of food (because then possibly IgE-mediated food allergy)
Risk factors for systemic reaction in OAS:
No pollen allergic sensitization - ?true food allergy
Large quantity of food eaten on empty stomach
PPI or other causes of increased gastric pH
Co-factors – NSAIDs, exercise
Peanuts, tree nuts, peach, and mustard associated with increased reactions
SCIT in OAS?
SCIT to associated pollens may be helpful in some patients (needs further studies) - Should not be given solely for this purpose
Birch allergens
- Bet v 1 (PR-10)
2. Bet v 2 (Profilin)
Ragweed allergens
Amb a 1 is the major ragweed allergen.
However, the Amb a 8 is the profilin allergen which is responsible for cross reactivity and PFS
What is latex- fruit syndrome?
Exposure to latex allergens can also sensitize individuals to plant foods.
30 to 50% of latex allergic patients can have hypersensitivity to plant-derived foods, especially fresh fruits:
avocado, banana, kiwi, chestnut, peach, tomato, white potato, and bell pepper
What is mugwort mustard syndrome?
Sensitization to mugwort, with allergy to mustard (severe allergic reactions to mustard may occur)
Patients may be sensitized to other foods within the Brassicaceae family: cauliflower, cabbage, broccoli (40% reported clinical symptoms with ingestion of these foods)
What is celery- mugwort spice syndrome?
Patients are sensitized to both birch and mugwort, and have an allergy to celery (allergic reactions to celery may be severe)
May react to other foods within the Apiaceae family (carrot, caraway, parsley, fennel, coriander, and aniseed), as well as to paprika, pepper, mango, garlic, leek, and onion
Name some PR 10 proteins (Birch protein)
Bet v 1 (birch) – the ones below are mistaken as Bet v 1
in each fruit
Homologous to bet v 1: Mal d 1 (apple) Pru av 1 (cherry) Pyr c 1 (pear) Pru ar 1 (apricot) Cor a 1 (hazelnut) Api g 1 (celery) ARA h 8 (peanut) Dau c 1 (carrot)
PRP 10 proteins are pollen cross reactive components
for birch
Risk factors for OAS
- multiple pollen sens
- sens to tree esp birch
- sx AR
- area with high pollen levels
- higher sIgE to pollens