Food Sensitivities, Allergic Reactions, and Food

1
Food Sensitivities, Allergic Reactions, and Food
Intolerances?????????????????
2
CONTENTS ????

• DEFINITION AND MECHANISMS OF ADVERSE FOOD
  REACTION??? ????????????
• SYMPTOMS OF ADVERSE FOOD REACTIONS??? ?????????
• DIAGNOSIS OF ADVERSE FOOD REACTIONS??? ??????????

3

• PREVALENCE??? ???
• FOOD ALLERGENS??? ?????
• FOOD ADDITIVES??? ?????
• FOOD LABELING IN RELATION TO FOOD SENSITIVITIES
  ??? ?????????????

4
DEFINITION AND MECHANISMS OF ADVERSE FOOD
REACTION??? ????????????
5
Fig.1 Classification of foods proposed by
EAACI ?1 EAACI??????
6
toxic food reactions ??????

• A classical toxic food reaction is scombroid fish
  poisoning, due to large amounts of histamine
• ???????????????????

7
Food intolerance ?????

• enzymatic (resulting from an enzymatic defect,
  e.g., lactase deficiency),
• ????(??????,???????)
• pharmacological (depending on the direct effect
  of, e.g., vaso-active amines naturally found in
  foods)
• ????(???????,??????????????)
• Undefined????

8
SYMPTOMS OF ADVERSE FOOD REACTIONS??? ?????????
9
IgE-Mediated Food Allergy???IgE-?????????
10
Characteristic ??

• Clinical manifestations of IgE-mediated food
  allergy can remain localized at the site of the
  primary direct contact, i.e., ??????????????
• the mouth ?
• throat (oral allergy syndrome)??(???????)
• the gastroiniesrinal tract (isolated
  gastrointestinal food allergy)???(???????????)

11
Skin Respiratory tract GI tract
Cardievascular S. ?? ??? ???
?????? 45 25 20
10
Figure 2 Classical symptoms of IgE-mediated food
ailergy ?2 ?IgE?????????????
12
Oral Allergy Syndrome (?)????????

• Allergen fresh foods( fruits and vegetables)
• ???????(??????)

13

• Symptom ??
• Itching of the lips, mouth, palate, throat
• ???????????????
• Hoarseness and/or swelling of the lips, tongue,
  uvula, and larynx
• ????,?????????????

14
Allergic Reactions After Ingestion of Food
(?)??????????

• Symptom ??
• 1)The main symptoms of gastrointestinal food
  allergy are vomiting, nausea, diarrhea, and
  abdominal pains (colics or cramps).
• ?????????????????????(???????)

15

• 2) Skin reactions include local or generalized
  pruritus, flush, urticaria, angioedema.
  morbilliform exanthema, and flare-up of atopic
  dermatitis
• ?????????????????????????????????????????????

16

• 3) The symptoms of the upper and the lower
  respiratory tract are rhinitis (sneezing,
  pruritus of the nose, nasal stuffiness, and nasal
  obstruction), larynx edema, cough, wheezing, and
  bronchial asthma.
• ??????????????
• ??(?????????????????)????????????????

17

• 4) Itching, redness, and watering eyes
  (conjunctivitis)
• ???????????(???).

18
Allergic Reactions After Inhalation of Food
(?)??????????

• Symptom ??
• respiratory symptoms ??????

19

• Allergen flour, n-amylase, green coffee, castor
  and soy beans, spices. egg white, and crustaceans
  
• ??????a-????????????????????????????

20
Allergic Reactions Following Skin Contact With
Food(?)????????????

• Allergen fish, shrimp, flour, and pork
• ?????????????

21

• Symptom ??
• Urticarial lesion ??
• Chronic contact with a food may induce protein
  contact, dermatitis in food handlers
• ?????????????????????????

22
Non-lgE-Mediated Immune Reactions????IgE????????
23
Heiner's Syndrome, Allergic Alveolitis, and
Hemorrhagic Gastroenteritis in Childhood(?)??Hein
er?????????????????

• DEFINITIONThe term Heiner's syndrome
  characterizes a milk-induced syndrome with
  pulmonary disease in infants.
• Heiner?????????????

24

• Symptom ??
• chronic or recurrent pulmonary intiltrates
  ????????????
• allergic alveolitis ??????
• a chronic rhinitis ????
• gastrointestinal blood loss ?????
• iron deficiency anemia ?????
• chronic cough ????
• recurrent fever ?????
• Anorexia ??
• Vomiting ??
• Colic ??
• Diarrhea ??
• Hemoptysis ??

25

• Control ????
• institution of a milk-free diet
• ???????

26
Gluten-Sensitive Enteropathy (Celiac
Disease)(?)????????(???)

• Definitiondamage to the small intestinal mucosa
  and symptoms of malabsorption
• ????????????????????????????

27

• Allergen ???
• Gliadin ?????
• present in wheat, rye, barley, and oat
• ?????????????????

28

• The peak incidence of symptoms is in infancy
  after the introduction of cereals
• ?????????????????????,??????
• A second peak occurs during the third decade.
• ????????????

29

• Symptom ??
• abdominal pain???????
• loose stools??
• anorexia??
• short stature????
• delayed puberty?????
• nutritional deficiencies????
• Dental enamel hypoplasia ???????
• recurrent aphthae?????

30

• Control ????
• Patients with celiac disease must avoid gliadins
  and related proteins permanently
• ??????????????

31
Dermatitis Herpetiformis (?)?????

• Definition ??
• chronic blistering disease
• ????????

32

• Symptom ??
• itchy ??
• sometimes burning ??????
• eruption of grouped vesicles on an erythematous
  ground ???????????????

33

• Some DH patients, even without gastrointestinal
  symptoms, may have villous atrophy similar to
  that seen in celiac disease
• ??DH???????????????????,?????????????????,????DH?C
  D??????
• The cutaneous manifestations may or may not
  respond to a gluten-free diet
• ???????????????????????????

34
Eosinophilic Gastroenteritis (?)??????

• Definition ??
• elevated eosinophil counts in blood and tissue
  eosinophilia with release of eosinophii major
  basic protein
• ???????????????,????????????????????????????????

35

• Clinical manifestations ????
• vomiting ??
• abdominal pain ????
• Diarrhea ??
• malabsorption ????
• bowel obstruction ???
• Ascites ??

36

• The cause of EG is unknown
• ??????
• food hypersensitivity has been suggested
• EG??????????

37
Utcerative Colitis (?)??????

• Definition ??
• an inflammatory bowel disease of unknown origin
• ????????????

38

• No adverse food reactions have been shown as
  causative of UC
• ??????????????UC

39
Allergic Vasculitis(?)??????

• Cause ??
• foods and food additives
• ???????

40

• Symptom ??
• allergic purpura (widespread hemorrhagic macules
  and papules, mainly on the lower legs)
  demonstrated by single challenges
• ?????(???????????,?????????)

41
Food Intolerance???????
42
Lactase Deficiency????????

• Definition ??
• Lack of the enzyme that cleaves milk sugar,
  lactose, gives rise to adverse reactions when
  lactose is consumed.
• ??????,??????????????----??????,????????

43

• The only food of which lactose is a natural
  constituent is milk (3.7 g/100 ml cows milk).
• ?????????????(3.7g/ml??)

44

• Classification ??
• 1) congenital lactase deficiency???????????
• 2) primary lactase deficiency???????????
• 3) secondary lactase deficiency??????????

45

• 1) congenital lactase deficiency???????????
• lactase is not present and symptoms will appear
  when the patient is breast-fed.
• ?????????,??????????????
• The congenital form is very rare
• ???????

46

• 2) primary lactase deficiency???????????
• seen in most of the world's population where the
  production of lactase decreases or disappears
  from the age of 2 to the teenage years
• ?2-10??,??????????

47

• Persistent high lactase activity in adult life
  occurs among relatively few ethnic groups
• ???????????????????
• northern Europeans and their overseas
  descendants????????
• a few African groups of pastoral tradition
  Bedouins and other Saudi Arabs????????????????????
  ??
• certain groups from west India and
  Pakistan????????????

48

• 3) secondary lactase deficiency??????????
• a consequence of pathological changes in the gut
  mucosa, as seen in celiac disease or
  inflammations.
• ?????????????????
• When the gut mucosa has regained its normal
  appearance the lactase production reappears
• ?????????,???????????

49

• The symptoms ??
• Diarrhea ??
• gas production ??
• Colic ??

50

• Control ????
• avoid all products containing even small amounts
  of lactose
• ????????????

51
PREVALENCE??? ???
52

• The total prevalence of food allergy/food
  intolerance is not known.
• ??????
• Estimates based on data from one country do not
  necessarily reflect the prevalence of another
  country
• ??????????????????????,??
• 1) frequency and duration of breast feeding
• ????????????
• 2)eating habits????
• 3) flora???

53
Children????
54
Food(?)??

• allergy to cow's milk, egg, and fish
  predominantly begins before the second year of
  age
• ????????????????2???
• allergy to fruit, legumes, and vegetables
  predominantly begins after the second year.
• ??????????????????2???

55

• Table 1 Prevalence of Rhinitis and Oral Itch in
  Danish School Children
• ??????????????????
• Age (yr) Rhinitis () Oral
  itch()
• boys/girls boys/girls
• 5-7 9.0/5.7 0/0.38-10
  8.5/7.1 0.8/1.111-13 14.0/8-5
  1.9/1.514-16 17.3/13.0 2.9/2.0

56
Food Additives (?)?????

• Adverse reactions to food additives are found in
  1-2 of school children
• 1-2???????????????
• The prevalence in younger children is not known.
• ?????????????

57
Adults?????
58
Food (?)??

• In European studies the majority of allergic food
  reactions in adults are caused by fruits.
  vegetables, and nuts and are related to pollen
  allergy
• ???,??????????????????????????,?????????
• The prevalence is around 5
• ????5??

59

• probably only 0,5 have symptoms other than oral
  itch.
• ????0.5????????
• The prevalence of allergy to milk, egg, fish.
  etc. is around 0.2,,????????????????????0.2

60
Food Additives (?)?????

• The estimated frequency was 0.03-0.15
• 1982?EEC?????????????????0.03-0.15

61

• In British the prevalence
• ????? ????0.026
• Dutch ?? 0.4

62
Contact Allergens (?)??????

• 10 Danish women have contact allergy caused by
  nickel.
• 10??????????????
• Up to 10 of these may benefit from a
  nickel-restricted diet
• ??10?????????????

63

• What is contact allergens?
• In dermally sensitized subjects ingestion of the
  contact allergen may cause skin flare reactions
  or other symptoms, e.g., in the gastroinlestinal
  tract
• ???????????????????????????????????????

64

• Contact Allergens
• fragrances ????
• food flavors(natural or synthetic)?????
• Nickel ?

65
Other Adverse Reactions (?)??????

• 1)Celiac disease????
• Causewheat gliadin and related proteins
• ???????????????
• The prevalence 0.2-0.5
• ???0.2-0.5

66

• 2) lactase deficiency ????????
• CauseLack of lactase
• ???????
• The prevalence varies from a few percent in
  northern European countries to almost the entire
  adult population in Asia and Africa
• ????????????????,??????????????

67

• Conclusion
• It is not known whether the prevalence of food
  allergy or intolerance is increasing
• ???????/??????????????
• The prevalence of pollen-related food allergies
  has increased.
• ??????????????????

68
FOOD ALLERGENS??? ?????
69
Definition ??

• Allergens are antigens that give rise to allergy
  .
• ????????????

70
Where is food allergens from?

• Pollen??
• Mammals????
• mites?
• other insects????
• foods??

71

• Component?????
• Proteins or glycoproteins with a molecular
  weight from 3 to 90 kDa, the majority ranging
  from 10 to 40 kDa
• ?????????????????,????3kDa?90kDa,????10kDa?40k
  Da??

72
The identified allergens

• the first three letters of the genus, space, the
  first letter of the species, space, and an Arabic
  number.
• XXX X X
• ? ? ?????
• For example Lol p 1 refers to the first pollen
  allergen identified from Lolium perennc, or rye
  grass
• Lol p 1??????????,??Lolium perenne ????

73
Classification ??

• "major" proteins for which 50 or more of the
  allergic patients studied have specific IgE
• ?????50?????????????IgE????
• "minorthe remaining allergens are considered
  minor
• ?????50?????????????IgE????

74
The Nature of Food Allergens????????
75

• To make a complete list of allergenic foods on a
  global basis is virtually impossible.
• ????????????????
• Whether a food allergen causes significant
  problems in a population is dependent on several
  factors
• ???????????????????????????????

76
(a)the potency of the allergen??????

• some are much more frequent sensitizers lhan
  others
• ???????????????????,
• e.g., ß -lactoglobulin in milk or ovomucoid from
  egg white
• ?????ß-????????????????

77
(b)the physiochemical properties????

• 1)The chemical structure, i.e., the amino acid
  sequence, and the tertiary structure
• ??????????,???????
• 2)heat stability ????
• 3)digestibility ????
• 4)Structural relationship with epitopes from
  nonfood allergens
• ???????????????????

78
(c) the frequency of exposure?????

• In Europe allergy to rice and buckwheat is
  uncommon.
• ???,?????????????
• In Japan rice and buckwheat are common food
  allergens
• ???,??????????????

79
(d) the route of exposure ????

• 1)aero-allergensgrasses, pollen of trees and
  herbs , house dust mites ,o cat dander
• ????????????????????????
• 2)work environmentbaker
• ????????
• 3)via the skinNatural rubber (latex)
• ????????

80
(e) cross-reactions to aero-allergens??????????

• 1) local species of grass, trees, and herbs and
  pollution
• ??????????????
• e.g., Allergy to hazelnuts is common in areas
  with many birch trees, where birch pollen hay
  lever is frequent
• ??????????????????,??????????????
• 2) air pollution????

81
(f) the age at which the allergen is
introduced???????????

• In early infancy an increased uptake of antigen
  takes place at a time when the gut-associated
  lymphoid tissue is still incompletely developed
• ?????,????????????????????,???????????

82
Allergens of Animal Origin???????????
83
Milk (?)??

• 1)Albumin, ß -lactoglobulin, and immunoglobulins
  of milk are the most important allergens in
  infants
• ??????ß-??????????
• 2) In older children ß -lactoglobulin, caseins,
  and I-lactalbumin may be more reactive.
• ???ß-??????????-????
• 3)in adulthood casein to be the most frequent
  allergen
• ??????

84

• cross-reactions????
• The majority of patients with allergy to cow's
  milk proteins will also react to proteins from
  sheep's and goat's milk
• ??????????????????????????????
• Cross-reactions between milk from these species
  is not always present.
• ????????????????

85
Eggs(?)??

• the second most frequent food allergen in small
  children after cow's milk
• ???????????????????
• Egg white proteins are reported to elicit
  allergic reactions more frequently than egg yolk.
• ???????????????

86
?????????
87

• cross-reactions????
• allergy to egg can be correlated to allergy to
  bird feathers
• ???????????????????
• the major cross-reacting determinants are the
  livetins from egg yolk.
• ????????????????????

88
Allergens of Plant Origin???????????
89
The vegetable foods that most commonly cause
hypersensitivity symptoms???????

• Peanut ??
• Peas ??
• Carrot ???
• parsley ??
• Celery ??
• Orange ??
• Strawberry ??
• Cereals ??

• hazelnut ??
• Walnut ??
• Brazil nut ????
• Apple ??
• Almond ??
• Peach ??
• Plum ??
• Cherry ??

90
The ranking lists vary depending on?????????????

• 1)the age of the patients
• ?????
• 2)the methods of diagnosis
• ??????
• 3)the geographic location of the population
• ????

91
Fruits, Nuts, and Vegetables (?)????????

• More than 90 of patients with sensitization to
  vegetable foods had concomitant sensitization to
  pollen 90
• ????????????????????

92

• In a group of birch pollen allergies the patients
  with additional hypersensitivity to nuts and
  apples had
• ????????????????????????????
• (1) more severe symptoms during the pollen season
• ???????????
• (2) higher values of IgE to birch and hazel
  pollen,
• ????????IgE???
• (3) a larger area of the skin prick test reactive
  to birch and hazel pollen compared to the group
  without apple and nut allergy
• ?????????????????,???????????????????????

93

• The symptoms ????
• Mainly from the mouth and pharynx, with itching,
  swelling of the lips, tongue, and throat.
  syndrome.
• ??????,???????????
• These symptoms are called the oral allergy
• ???????

94

• cross-reactions????
• 1)A sensitization to mugwort pollens and
  different spices, the so-called
  mugwort-celery-spices syndrome, has been reported
• ??????????????????,????-??--??????

95

• 2) It was shown by prick, RAST studies, and RAST
  inhibition experiments
• ?????RSAT????RSAT??????
• a celery-thermolabile allergen seems to be
  involved in celery-birch-pollen-allergic patients
• ???????????????-??-?????
• a thermostable allergen is involved in celery
  -mug wort-allergic patients.
• ????????????-?????

96

• Pollen-related food allergies are thought to be
  caused by cross-reactions of pollen-specific IgE
  antibodies with epitopes of food proteins.
• ????IgE????????????????????,????????????

97
Three distinct cross-reactive structures in
pollen and vegetable foods???????3?????????

• 1) Bet v l is the major birch pollen allergen
• Bet v 1???????????
• Allergens with cross-reactivity to Bet v 1
• ?Bet v 1??????????
• Apples ??
• Hazelnuts ??
• cherries ??

• Pears ??
• Celery ??
• carrots ???

98

• 2)Profilins are widely distributed in the plant
  kingdom and have been identified as "plant pan
  Allergens."
• Profilin?????????,?????pan???
• 10 to 20 of the pollen-allergic patients are
  sensitized to pronlins.
• 10-20???????profilins??

99

• 3) Cross-reactions of allergen-specific IgE
  antibodies can be caused by so-called
  "cross-reactive carbohydrate determinants" of
  food and pollen glycoproteins.
• ????????,??? ??????????????????????IgE???????
  ?

100
Cereals (?)??

• two major allergens
• ???????IgE
• one at 47 kDa
• one at 20 kDa

101

• When challenged with double-blind,
  placebo-controlled food challenge
• DBPCFC????
• 21 of the patients with suspected allergy to
  cereals had symptoms
• 21???????????
• 8 had clinical reactions to only one cereal
• 8?????????????
• The majority of the children had clinical
  reactions to wheat (76)
• ?????(76)????????

102
Legumes (?)??

• Peanut allergy may be the most common food
  allergy in the United States
• ???,???????????????
• Allergic reactions are often acute and severe
• ?????????????

103

• The major peanut allergen
• ????????

Ara h 1, molecular weight of 66 kDa

glycoprotein ???
Ara h 2, molecular weight of 17 kDa
104

• The characteristic??
• heat stable ????
• a potential source of "hidden food allergens
• ???????????????

105
Natural Rubber (Latex)-Related Food
Allergens(?)?????(??)???????

• The latex allergens are proteins from the rubber
  tree
• ???????????????
• Common antigenic determinants demonstrated
  between latex and avocado, chestnut, and banana
• ??????????????????????

106

• Allergy to natural rubber (latex) has become
  increasingly problematic????(??)????????
• These reactions are severe, e.g., anaphylactic
  shock
• ????????,??????

107
FOOD ADDITIVES??? ?????
108

• Chemically and functionally food additives are a
  very heterogeneous group of substances consisting
  of
• ?????????????????
• Enzymes ?
• Flavors ???
• Colors ??
• Preservatives ???

Emulsifiers ??? Antioxidants ???? Sweeteners ???

109
Colors????
110
Azo Colors (?)????

• The azo colors cause adverse reactions
• ????????????
• tartrazine???
• sunset yellow???
• azorubin/carmoisin????

amaranth??? ponceau 4R???4R
111

• Symptoms
• mainly on the skin and mainly
  urticaria
• ????????

112

• Tartrazine has been the additive of choice when
  researchers have tried to elucidate the mechanism
  of food-additive intolerance
• ??????????
• a pharmacological effect of tartrazine and other
  azo colors
• ?????????????????

113

• pharmacological effect
• ?????
• a large cumulative dose of tartrarine (200 mg)
  in normal subjects resulted in a significant rise
  in plasma and urinary histamine levels.
• ???????????????,??????????????
• The histamine release was not accompanied by
  systemic symptoms
• ????????????????????

114
Nonazo colors (?)????

• Nonazo colors could give adverse reactions
• ????????????
• Annatto ??
• Indigo ??
• Carmine ???
• Erythrosine ???
• patent blue ???(???????)

115

• Symptoms
• mainly on the skin and mainly
  urticaria
• ?????????

116
Preservatives?????
117
Benzoic and Sorbic Acid (?)????????

• causes of urticaria
• ???????
• provoke itching and tingling in the mouth
• ??????????
• The mechanism is not known
• ???????

118
Sulfites (?) ????

• symptoms ??
• asthma ??
• anaphylactic reactions ????
• symptoms on the skin ?????

119
the likelihood of a reaction depend
on???????????

• The nature of the food?????
• the level of residual sulfite?????????
• the sensitivity of the patient??????
• the form of residual sulfite?????????
• the mechanism of the sulfite-induced reaction
• ??????????

120
the cause of asthmatic reactions to sulfltes in
food???????????

• inhalation of sulfur dioxide liberated during
  ingestion
• ??????????
• deficiency of sulfite oxidase
• ?????????

121
Metabisulfite ??????

• Metabisulfite-induced basophil histamine release
  in a nonasthmatic patient
• ?????????????????????
• developed urticaria and angi oedema following
  provocation with sodium metabisulfite
• ???????????????????
• an IgE-mediated reaction
• ??????????????IgE??????

122
Flavor Enhancers and Flavors??????????
123
Flavor Enhancers Monosodium Glutamate
(?)???????

• The result of monosodium glutamate (MSG) was the
  Chinese restaurant syndrome (CRS) and asthma?
• ?????
• ???????(CRS)
• ???

124

• 1)symptoms of CRS ??
• headache ??
• a burning sensation along the back of the neck
• ??????????
• chest tightness ??
• Nausea ??
• Sweating ??

125

• Symptoms characteristic of the Chinese restaurant
  syndrome can be provoked in a limited number of
  individuals by high concentrations of MSG,
  reaching a frequency of about 30 at
  concentrations higher than 3 g/100 ml.
• ???????3g/100ml?,????30???

126

• Where MSG is used in very high amounts. Chinese
  restaurant syndrome can be provoked in sensitive
  subjects.
• ??????????????????????,??????????
• Wonton soup may contain up to 5 g of MSG per bow
  
• ?????????5g

127

• 2)Asthma??
• Whether MSG induces asthma is currently still
  under debate.
• ??????????????????????

128
Flavors (?)??

• Fragrance materials used in perfumes and other
  cosmetic products can cause allergic contact
  dermatitis.
• ????????????????????????
• Many of the chemical substances in fragrances are
  identical to chemicals found in food flavors.
• ??????????????????????

129

• A number of the 30-40 chemicals in balsam of Peru
  are identical or closely related to chemicals
  present in spices and food flavors (e.g.,
  vanillin, eugenol, cinnamic aldehyde)
• ??????????????(?????????????)?30-40????????
• Balsam of Peru is used in the standard patch test
  series in dermatology to test for contact allergy
  to fragrance materials.
• ???????????????,??????????????????

130

• Control ????
• Forty-seven percent of the patients placed on a
  balsam-restrictive diet showed long-term
  improvement.
• ????????,47?????????

131

• Difficulty ??
• Chemical flavor are found in all plants in
  various amounts
• ?????????????
• It was difficult to pinpoint one causative
  chemical and to design an effective diet?
• ????????????????????,??????????????

132
Solvents Propylene Glycol???????
133
APPLICATION ??

• a solvent of flavors ????
• food industry ????
• cosmetics ???

134
Special application

• It gives cakes a nice soft texture
• ????????????
• The manufacturer to use it in larger amounts than
  its function as a solvent can justify..
• ??????????????????

135

• Symptoms ??
• Extensive exanthem (reddening of the skin) within
  3-16 h of ingestion
• ??3-16h????????(????)
• Subsided without any medication in 24-48 h.
• ???????,24-48h???????

136
Antioxidants??????
137

• BHA?BHT
• flare-up contact allergy after ingestion of BHA
  or BHT
• ????????
• chronic urticaria
• ????

138
Enzymes and Vegetable Gums ???????
139

• CharacteristicIgE-mediated allergic reactions
• ???IgE????????
• Exposure pathway
• 1)inhalation in the workplace
• ??????
• 2)papain used as a meat tenderizer via the
  respiratory route is also a possibility.
• ???????----??????????

140
THE END!