Food Allergy Flashcards

1
Q

Two stems off of Food Allergies are

A

Immunologic:
Type: I, III, or IV

Non-immunologic:
Food intolerance
Dietary indiscretion

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2
Q

Food Allergy

Pathogenesis

A

Not completely understood

Exposure to allergens
Development of immune response (oral tolerance)
Activation of immunogenic pathway

M cells in GI tract capture antigen –> present to antigen presenting cells in Peyer’s Patch –> travel to lymph nodes –> IgA

Involves:
Histamine
Proteases
Chemotactic factors

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3
Q

What disease is thought to predispose animals to food allergies?

A

GI disease

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4
Q

Food Allergy
Antigen Types
Dog

A

10,000-30,000 Daltons

Beef
Chicken
Dairy products
Wheat
Soy
Lamb
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5
Q

Food Allergy
Antigen Types
Cat

A

10,000-30,000 Daltons

Beef
Dairy products
Chicken 
Fish
Lamb
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6
Q

Food Allergy
Clinical Features
Dog

A

Usually less than 1 year of age

Non-seasonal pruritus

Affects:
Ventral hairless area
Face
Feet
Peri-anal 

Think: ears and rears

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7
Q

Food Allergy
Secondary Issues
Dog

A
Otitis (recurring) 
Recurrent pyodermas
GI signs
Vasculitis
Urticaria
Erythema multiforme (target lesions; suggestive of hypersensitivity) - antigen driven
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8
Q

Food Allergy
Clinical Features
Cats

A

Age: 4-5 years

Pruritus (head and neck)

Reaction Patterns:
Miliary dermatitis
Eosinophilic granuloma complex

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9
Q

Pruritus

DfDx

A
Atopic dermatitis (diagnosis of exclusion)
Drug reactions 
Contact hypersensitivity
Flea allergy
Scabies
Yeast dermatitis
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10
Q

Diarrhea

DfDx

A

GI parasites
IBD
PLE
GI lymphoma (older patients)

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11
Q

Food Allergy

Diagnosis

A

Elimination diet and provocative exposure
Will take time
Trials: 3-12 weeks (6-8 recommended) with a STRICT regimen

Allergen avoidance

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12
Q

Food Allergy

Allergy tests

A

Intradermal skin testing
Allergen-specific serum IgE
Patch testing

All are NOT effective

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13
Q

Food Allergy

Medication Causes

A

Flavoring additives!

Vitamins
Supplements
Prevenatives: heartworm, flea
Arthritis medication
Urinary incontinence medication
Dental products 

Must keep this in mind during diet trial

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14
Q

Pruritus Rx

A

Corticosteroids; may not work which further supports food allergy

Apoquel

Cytopoint

Note: still must determine underlying cause of pruritus

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15
Q

Types of Diets Used for Diagnosis

A

Home-made; gold standard but must be done through nutritionist monitoring
Can make it for the individual (control)

Novel protein diets

Hydrolyzed

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16
Q

Novel Protein Diets

A
Rabbit
Kangaroo
Venison (beef)
Duck
Fish 
\+/- pork

Keep in mind taxonomic relationships (ex. duck and poultry)

Look at the ingredients some claim to be novel protein diets but the third-fifth ingredient is actually chicken or beef

If losing weight may need to switch diet

17
Q

Hydrolyzed Diet

What is it?

A

Peptide bond in amino acid chains are broken to generate smaller fragments (reduces allergenicity and improves digestibility)
Not complete hydrolyzed b/c decreases palitability

Molecular weight less than 10,000 Daltons; less likely to be targeted by immune system

Protein does not have to be a novel source

May still not work for some animals

18
Q

Hydrolyzed Diets

Exmamples

A

Royal Canin:
Ultamino (duck feathers); 99% peptides are <6,000 Daltons which is promising
PS (potato and soy)
HP (soy/brewers rice)

Hills:
z/d and z/d ultra

Purina:
HA (soy)

19
Q

Food Allergy

Grain Free

A

Does not help with food allergy because food allergy is often due to protein not the grain

Marketing scheme

Corn is not allergenic
Grain actually provides nutritious source of carbs and essential amino and fatty acids for skin

20
Q

OTC Allergy Foods

What to be wary of

A

CHECK THE INGREDIENTS

May not be as they claim

Studies have shown these diets may contain protein snot listed in ingredient list!

Cross-contamination also common; not required to clean machine in-between switching from one food to the next
Also, transport vehicles/containers are not cleaned

21
Q

Food Allergy
Diagnostic Approach
History

A
Pruritus? (should be yes)
Age of onset (young)
Seasonal (environmental) vs Non-seasonal (food)
Infections (skin/ear)
GI symptoms? (yes)
22
Q

Food Allergy

PE findings

A

Pyoderma

Otitis

23
Q

Food Allergy

Pyoderma Rx

A

Must treat for 3-4 weeks with re-check

First tier:
Cephalexin
Simplicef
Convenia (repeat in 14 days)
Clavamox 

Only use second tier with C/S results

24
Q

Food Allergy

Otitis Rx

A

May see bacteria and/or yeast
q12 hours for 10-14 days

Otomax
Miconazole/Dex
Osurnia

25
Q

Food Allergy

Pruritus Rx

A

Usually treating for about a month and pruritus should resolve if diet is correct

Cytopoint
Apoquel
Temaril-P

26
Q

Food Allergy

Diagnosis with Food Trial

A

Dietary challenge:
6-8 weeks

If animal goes off diet and then there is a flare up the diet did work and food allergies are confirmed
Reaction may be seen 2 hours to 2 weeks after diet switch