By the scientific direction of the NBF-Lanes with the advice of Dr. Fabrizio Fabbrini.
Atopic dermatitis, as it is a chronic disease of genetic base, cannot be eliminated but managed by setting a nutritional therapy that can alleviate the symptoms and lesions, prevent secondary infections and increase the quality of life, both to the patient and his owner.
GENERALITY
Atopic Dermatitis (AD) is an itchy skin disease of genetic / hereditary basis, with facial, ventral and podal involvement, relapsing or chronic, characterized by distinctive clinical manifestations and associated with the production of IgE against environmental allergens (pollen, dust mites, mold, etc.) and / or food.
It is a multifactorial disease, where in addition to genetic predisposition / family, are called into question:
- Abnormalities of the immune response: type I hypersensitivity
- Biochemical abnormalities: deficiency in delta-6 desaturase with lower production of PGE1 and DGLA
- Alterations of the lipid barrier: function deficiency in ceramides with increased trans-epidermal water loss (TEWL) and consequent xerosis, increased percutaneous passage of allergens and increased surface microbial proliferation
Currently, food-borne proteins are also considered as possible allergens causing the AD. Often allergy sufferers can develop multiple sensitizations: to pollen, dust mites and / or food, to food proteins and to insect bites. Finally, it should be noted that often the allergic dogs have secondary opportunistic infections: otitis and pododermatitis yeast or bacterial, pyoderma and / or Malassezia dermatitis.
The diagnosis of AD is not based on the results of allergy tests; it is a clinical diagnosis of exclusion: the presence of at least 3 clinical postulated by Pascal Prelaud criteria (age of onset between 6 months and 3 years; presence of cortical-sensitive itching, presence of bilateral otitis externa; presence of cheilitis; presence podo-dermatite of the front limbs) in the absence of ectoparasites and infections, is used to confirm the diagnosis with a sensitivity and specificity of 80%. Only after having established clinically that it is a AD, and evaluated the presence of a possible sensitization to food (through a diet elimination) it may be possible to perform allergy testing in order to identify the allergens for use in desensitization therapy.
The AD therapy
Since Atopic dermatitis is a chronic disease of genetic base, cannot be eliminated but managed by setting a nutritional therapy that can alleviate the symptoms and lesions, prevent secondary infections and increase the quality of life, both to the patient and his owner.
The options are:
- Eviction allergen: you can remove only the food allergens from the diet
- ASIT or allergen-specific immunotherapy: in addition to desensitize it help to prevent sensitization to other environmental allergens
- Symptomatic treatment for itching: use of corticosteroids, antihistamines and / or Cyclosporine A
- Local or systemic antimicrobial therapy
NUTRITIONAL THERAPY
Since this is a multifactorial disease, nutrition has the following indications:
- Helping to restore the barrier function: some in vitro and in vivo studies showed that the nicotinamide, pantothenic acid, histidine, inositol and choline, are capable of improving the structure and function of the skin, leading to a reduction of TEWL and xerosis and consequently a lesser percutaneous penetration of allergens and a limited microbial surface colonization; other studies show that the proline and pyridoxine are capable of stimulating the synthesis of ceramides and linoleic acid (L.A.) is an integral part of cell membranes and skin protective barrier.
- Modular and reduce the inflammatory process: the essential fatty acids (EFA) ω-3 and ω-6 have both physiological effects and pharmacological effects.
DGLA and EPA are in competition with arachidonic acid in the production of eicosanoids, those derived from DGLA and EPA (PGE-1, PGE-3) has anti-inflammatory effects. In addition, there is a synergistic action between EFAs and cortisone and antihistamines (allowing a reduction in their dose therapy). The curcumin, by acting on the immune response (inhibits the activation of mast cells, the synthesis of lipoxygenase, cyclooxygenase, and immunoglobulins), reduces the inflammatory response.
- Diagnose, prevent and control food hypersensitivity: there are commercially available balanced mono-proteins diets, based on seafood, duck, venison, quail, rabbit, goat, pig; or balanced hydrolyzed diets based on animal protein (chicken) or vegetable (soy, corn) useful in the diagnostic phase (elimination diet for a period of 8-12 weeks) than in therapeutic and preventive phase.
- Help prevent, prophylaxis, the development of AD in susceptible individuals: based on data obtained in medicine on the use of probiotics (which induce production of IL12 and inhibit the production of IgE) during pregnancy and lactation in mothers with strong predisposition allergic (where he showed a lower incidence of allergic reactions in children); Rossana Marsella, in a pilot study, treated Beagle allergic prepared with Lactobacillus GG and during gestation from 21 to 180 days of age. After sensitization to dust mites treated pups showed:
– a. lower production of allergen-specific IgE
– b. lower reactivity to skin test with D. farinae
– c. lower incidence and severity of clinical signs of atopic D.
In humans, it has always shown that dietary supplementation with polyunsaturated fatty acids (PUFAs) during pregnancy and lactation, helps to reduce clinical food hypersensitivity in children, encouraging the development of an immune response of type Th -1.
CONCLUSIONS
Several studies confirm the importance of diets rich in proteins and lipids of high quality and with high levels in ω-3 and ω-3-6 in the course of the AD in the dog; the reported beneficial effects are dependent on:
- Itch
- Erythema
- CADESI (Gravity and Extension D. Atopic Index)
- Quality of the coat
From the above, it is clear that dietary intake is important not only in the management of deficiency forms, but also for:
– Restore the Anatomy and physiological skin functions
– Modular inflammatory response in the course of dermatitis
– Decrease the dosage of steroids and antihistamines in therapy
– Check the food hypersensitivity
– Preventing / modulate the development of allergic diseases by the use of probiotics
