Page 199 - WSAVA2017
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WSVA7-0299
GLOBAL NUTRITION
DERMATOLOGY AND DIET - CURRENT PERSPECTIVES
T. Nuttall1
1University of Edinburgh, Royal Dick School of Veterinary Studies, Roslin, United Kingdom
DERMATOLOGY AND DIET – CURRENT PERSPECTIVES ON FOOD TRIALS
Dr Tim Nuttall
Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Roslin, UK.
tim.nuttall@ed.ac.uk
Introduction
The skin has complex nutritional requirements. Adverse food reactions (AFRs) have been recognised for many years but the relationship between diet and skin disease involves more than allergies. This lecture will discuss current views from the perspective of a dermatologist and a nutritionist.
How might diet affect the skin?
Potential factors affecting the skin include:
• Food intolerance (e.g. lactose)
• Toxic or pharmacological reactions
• Type 1, 2, 3, 4 or mixed hypersensitivity reactions
• Novel proteins
• Hydrolysed proteins
• Increased digestibility
• Probiotics and prebiotics
• Altered fat content and essential fatty acids
• Changed or reduced additives
• Isoflavins and other immunomodulators
These are not mutually exclusive and clinicians should therefore carefully evaluate each patient before deciding on the most suitable diet for diagnosis of AFRs and management of skin conditions. The needs of other body systems and weight management must also be considered.
AFRs and food-induced atopic dermatitis
We now differentiate cutaneous AFRs from food-induced atopic dermatitis (FIAD). There is a complete response
to diet restriction-provocation in AFRs. In FIAD there
is a partial response to diet restriction-provocation
– foods can be a trigger for AD but sensitisation to environmental allergens, a poor skin barrier, and altered skin inflammation also contribute.
Clinical signs of AFRs and FIAD
Most start between 1 and 4 years of age, with 30-
50% starting <1 year (compared to 16% of non-food associated AD). The foods may have been fed for 2 years or more. Clinical signs are non-seasonal, with seasonal flares associated with concurrent environmental allergies. Skin and GIT signs are seen in 30-60% of dogs and 10-30% of cats. Head and neck dermatitis is particularly associated with feline AFRs. Oral allergy syndrome
(IgE mediated pruritus and swelling of the lips and oral cavity) has been recognised in dogs sensitised to Cry j 3 (Japanese cedar; Cryptomeria japonica) that cross-reacts with tomato but foods may also stimulate acute sneezing and conjunctivitis.
Food allergens
Any protein can be an allergen. Most dogs react to more than one (mean 2.4), although the data is limited by inconsistent provocation studies.
An Urban Experience
   Skin (dogs)
   Pruritus Urticaria Angio-oedema Anaphylaxis Oral allergy syndrome
   Skin (cats)
  Eosinophilic granuloma complex Head & neck dermatitis Self-induced alopecia Indolent ulcer
   GIT
 >3 bowel movements/day Soft and/or variable faecal consistency Flatulence & borborygmi Intermittent vomiting or diarrhoea Colitis
 Other
   Altered demeanour Neurological problems Sneezing & conjunctivitis Urinary tract
  International Committee on Allergic Diseases in Animals: Position paper on food allergens
      Dogs (n=297)
   Cats (n=78)
 Beef
  34%
  18%
  Dairy
 17%
  4%
 Chicken
 15%
 5%
 Lamb
 14%
 -
 Wheat
 13%
 4%
 Soy
 5%
 -
 Maize
 6%
 4%
 Egg
 4%
 1%
 Pork
  4%
  -
  Fish
 2%
  17%
 Rice
  2%
  -
 Most allergens are 10-70 kD glycoproteins. Specific allergens in dogs include bovine serum albumin, muscle phosphoglucomutase, and bovine and ovine IgG.
Cross-reaction between food allergens
There is significant co-sensitisation and/or cross-reaction among food allergens, which is more frequent and
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