Pathophysiology of atopic dermatitis in dogs
Atopic dermatitis in dogs is the leading cause of chronic pruritus in dogs and cats. It is a complex, multifactorial disease involving interactions between skin structure, the immune system and environmental influences.
Osteoarthritis is one of the most common chronic musculoskeletal diseases and is a cause of lameness and disability in dogs (Colitti et al., 2012).
It is a complex and multifactorial disease involving interactions between skin structure, the immune system and environmental influences (Bensignor, Morgan, and Nuttall 2008). On the one hand, animals suffer from an inherited predisposition to develop immediate hypersensitivity reactions, mediated by IgE antibodies against environmental allergens (Olivry and Hill 2001)(Fidalgo Álvarez et al. 2007). On the other hand, animals suffer from an alteration of the insulating function of the epidermis, of genetic or acquired origin, based on the mutation of a protein, filaggrin, one of the essential components constituting the epidermal barrier and changes in the organization of the stratum corneum lipids (Carlott 2005). The dysfunction of the skin barrier would be responsible for an increase in the penetration of allergens via percutaneous route and also for an increase in transepidermal water loss.
Check out our guide to the most common diseases in dogs.
The clinical picture observed is the consequence of a type I hypersensitivity reaction in the first phase of which the formation of IgE immunoglobulins to specific allergens and the sensitization of mast cells take place, so that in the second and subsequent contact with allergens, the sensitized cells degranulate vasoactive substances such as histamine, prostaglandins and leukotrienes that trigger a pruritic inflammatory process (Brazís et al. 1998).
The most characteristic is erythema in the facial area (muzzle, periocular region, auricular pavilion and external auditory canal), distal zone of the front and hind legs (flexion zones of the extremities and interdigital spaces), inguinal, axillary, perianal and abdominal areas, generally without other types of lesions (Fidalgo Álvarez et al. 2007).
Secondary infections (bacterial or Malassezia) and scratching play a fundamental role, as they help to keep the inflammatory response active. The chronification of pruritus ends up causing lichenification, hyperpigmentation and hypotrichosis in the most affected areas (Hand et al. 2010). Discover our post on Supplements and vitamins for dogs.
Dermakun nutraceutical from the Skin Recovery line treats atopic dermatitis, reduces the associated itching and counteracts its side effects by improving skin barrier function, decreasing allergic inflammatory response and supporting skin healing.
REFERENCES
Bensignor, E.;, Morgan D.M.; Nuttall, T., 2008. Eficacia de una dieta enriquecida con ácidos grasos esenciales en el tratamiento de la dermatitis atópica canina: A randomized, single-blinded, cross-over study. Veterinary Dermatology, 19, 156-162.
Brazís, P.; Queralt, M.; De Mora, F.; Ferrer, Ll.; Puigdemont, A., 1998. Estudio comparativo de la liberación de histamina por mastocitos cutáneos dispersos de perros atópicos, sensibles a ascaris y sanos. Veterinary Immunology and Immunopathology, 66, 43-51.
Carlott, D.N., 2005. Dermatitis atópica canina: Nuevos conceptos. Clínica Veterinaria de Pequeños Animales, 25, 43-47.
Fidalgo Álvarez, L.E.; Rejas López, J.; Ruiz de Gopegui Fernández, R.; Ramos Antón, J.J., 2007. Patología médica veterinaria (Universidad de León, Ed.) 1ª edn.
Hand, M.; Thatcher, C.; Remillard, R.; Roudebush, P.; Novotny, B., 2010: Nutrición clínica de pequeños animales. (Mark Morris Institute, Ed.) 5ª edn.
Olivry, T.; Hill, P.B., 2001. El grupo de trabajo ACVD sobre dermatitis atópica canina (IX): The controversy surrounding the route of allergen challenge in canine atopic dermatitis. Veterinary Immunology and Immunopathology, 81, 219-225.
