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Eosinophilic Dermatitis Treatment

Written by Megan Kinder [email protected]

A generalized, chronic, progressive, exfoliative, eosinophilic dermatitis treatment in five horses is described. Histologically, the lesion is characterized by a superficial and deep perivascular dermatitis which is eosinophil-rich with a marked lymphocytic and plasmacytic component, accompanied by marked acanthosis and hyperkeratosis. More severe cases progress to a lichenoid pattern with the same cellular composition with focal eosinophilic spongiosis and eosinophilic subcorneal pustules. Clinically, the disease is associated with chronic, severe weight loss and is fulminating. The skin lesions are accompanied by lympho-plasmacytic and eosinophilic infiltrates and formation of eosinophilic granulomas in other epithelial organs, most noticeably the pancreas, in which a chronic, fibrosing pancreatitis develops. Other epithelial organs involved to various degrees are salivary glands, the gastrointestinal system, including the oral cavity and esophagus, biliary epithelium and bronchial epithelium. The etiology of this disease is unknown, but here we are examining the Eosinophilic Dermatitis Treatment used.

Eosinophilic Dermatitis Treatment in 5 Horses

All horses had a generalized dermatitis of several months duration and severe weight loss despite good, often ravenous, appetite. None had diarrhea. The dermatitis usually began as a dry, scaly or cracking and oozing inflammation around the coronets or head  and oral cavity . It then spread to involve the entire body with a dry, exfoliative dermatitis, easily epilated hair and focal alopecia . This progressed rapidly to become cracked, excoriated, alopecic, ulcerated, exudative and secondarily infected. The condition was thought to be pruritic in two in stances and nonpruritic in the remainder. Four of the horses were treated with immunosuppressive doses of corticosteroids and none showed significant improvement. 

Diagnostic procedures of the Eosinophilic Dermatitis Treatment

Hematological values were unremarkable in all four horses examined. None of these had peripheral eosinophilia. Immunofluorescent tests done in two horses resulted in nonspecific staining only. Bacteriological and virological techniques failed to identify any likely pathogen. Necropsy findings: Gross lesions. Dermatitis was similar in all horses. Horse 3 had the earliest and mildest lesions. The other cases varied from each other only in the amount of excoriation and secondary suppuration. The pancreatic lesion
in horses, 2, 3. and 4 was striking. The affected organs were up to eight times normal size, very white and firm, and homogeneous on cut section. Horses 1 and 5 had only part of the pancreas affected this way. The hyperkeratosis of the esophagus and nonglandular stomach was very marked in three horses. The mucosa was thrown into stiff folds that resembled a plaster cast of the organs involved, in horse 2.

Histopathological findings of the Eosinophilic Dermatitis Treatment

There was a range of lesions in the skin that varied from the mildest in horse 3, to severe and complicated by ulcers, exudate, excoriations and secondary, suppurative inflammation in the others. Acanthosis and hyperkeratosis with foci of parakeratosis and with crust and scale formation were seen in all skin sections. The epidermal lesions progressed to focal spongiosis with eosinophil exocytosis and eosinophilic subcorneal pustules. There were also areas of ulceration and exudation with a neutrophil-rich dermal response and focal eosinophilic or neutrophilic furunculosis and neutrophil-rich subcorneal pustules. These last lesions were most likely due to secondary bacterial infection. 

The dermal reaction was a superficial and deep perivascular dermatitis with lympho-plasmacytic and eosinophilic predominance. In some areas the mononuclear cells were more numerous and eosinophils were locally scanty, whilst other areas had a preponderance of eosinophils. The lesion progressed, in more severe cases, to a lichenoid pattern with the same cellular composition. Eventually, diffuse involvement of the whole dermis with eosinophils and lymphocytes, principally, and an early, diffuse dermal fibrosis occurred.

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