Oral Allergy Syndrome

1
Oral Allergy Syndrome
2
What is it?

• Oral allergy syndrome is a type of food allergy
• mainly affects people with springtime hay fever
• is caused by a cross-reaction, between antibodies
  to pollens (usually birch), and allergens in
  foods
• It is characterised by symptoms of itching and/or
  swelling in the mouth and/or throat when eating
  certain fruits vegetables and nuts within minutes
• can get local swelling of the mouth
• or even urticaria, conjunctivitis, wheezing and
  vomiting
• Anaphylaxis is rare

3
Common foods are...

• Fruits
• Apple, citrus, kiwi, tomato, melon
• Nuts
• Vegetables
• Carrots, celery, spinach, potatoes (never eaten
  raw!!)
• And usually not when they are cooked (except nuts
  and celery)
• There is a wide range however, and certain oral
  allergens are associated with different pollens
  (birch, grass, ragweed) or even latex allergy

4
Prevalence and other features?

• Cant find a prevalence
• 25 of people have some sort of hay fever at some
  time in their life. OAS much less common
• Tends to come on later than hay fever. HF starts
  most commonly in teenagers, and OAS in the 20s
• Oral antihistamine is often all that is needed,
  if anything, because the treatment is avoidance

5
Tests?

• Not very good (only one place uses raw food
  extract)
• Mainly on history of hay fever and clear story
• If the patient wants to test for it, as long as
  they only get oral symptoms, they can rub some of
  the cut fruit on their lip, and wait. If that is
  ok, take a bite, chew and spit it out, and wait
  15 minutes

6
Mrs OAS - Dr

• Mrs OAS is a 25 year old office worker whom you
  know for her cocp and her early spring hay fever

7
Mrs OAS aged 25

• You are a 25 year old office worker for Lloyds
  TSB, who has hay fever worse in March and
  April. You have started to experience a tingling
  soreness in your mouth while eating some foods.
  Recently when you eat a salad, your tongue began
  to swell and you went to AE. By the time you
  were seen there it had all settled, and they said
  there must have been something (an insect?) in
  the salad. It has happened again when you had a
  lightly grilled tomato on toast. You eat a lot of
  pizza with tomato sauce, so are sure it cannot be
  this. You are quite worried, and a bit
  sensitised (!) because you feel you have been
  fobbed off.