Chronic eosinophilic dermatitis: a manifestation of a multisystemic, eosinophilic, epitheliotropic disease in five horses.

The research paper presents a study on a severe, long-term skin condition, observed in five horses, linked to multisystemic eosinophilic disease affecting various epithelial organs, including the pancreas.

General Observation and Disease Description

• The research describes observations of a chronic and progressive skin disease found in five horses. This skin disease, characterized by peeling of the skin or exfoliative dermatitis, was recognized as a manifestation of a multisystem disease affecting several organs of the body.
• The skin disease is marked by a deep and superficial inflammation around blood vessels, filled mainly with eosinophils, a type of disease-fighting white blood cell, along with a significant presence of lymphocytes and plasma cells.

Disease Progression

• In more severe cases, the condition takes on a lichen-like pattern, still dominated by the same cellular composition, but with incidences of visible focal spots of eosinophilic spongiosis, a condition marked by intercellular edema in the epidermis, and subcorneal pustules filled with eosinophils.
• Associated clinical signs of the disease include chronic weight loss. The severity of the condition often leads to a fulminating or rapidly worsening state.

Systemic Involvement and Organ Affection

• Aside from skin lesions, the disease is also characterized by the presence of lymphoplasmacytic and eosinophilic infiltrates, along with the formation of granulomas or nodules in various organs. These are largely spotted in epithelial tissues, which line the outer surfaces of organs and blood vessels throughout the body.
• Most significantly, the pancreas is affected, resulting in chronic, fibrosing pancreatitis, a condition where persistent inflammation leads to scarring and hardening of the organ.
• The illness also affects salivary glands, the gastrointestinal system, including the oral cavity and esophagus, biliary epithelium, and bronchial epithelium to varying degrees.

Unknown Etiology

• The cause of this disease remains unknown to researchers. The observations and descriptions presented in the study can facilitate further research to discover the etiology of this disease.