Psoriasiform-lichenoid-like dermatosis in three dogs treated with microemulsified cyclosporine A.

Cyclosporine has been reported to be effective for the treatment of various cutaneous autoimmune disorders in dogs. Adverse reactions have generally been limited to gastrointestinal tract disturbances and cutaneous eruptions. The article describes antimicrobial-responsive cutaneous reactions in 3 dogs being treated with microemulsified cyclosporine A because of various dermatologic conditions. Cutaneous reactions in these dogs were similar to psoriasiform-lichenoid dermatitis and may represent an atypical staphylococcal infection.

Idiopathic benign lichenoid keratosis on the pinna of the ear in four dogs.

Histologically, multiple wart-like papules or hyperkeratotic plaques on the ear pinnae from 4 dogs were characterized as idiopathic benign lichenoid keratosis. Common histologic features included a discrete lesion of irregular and papillated epidermal hyperplasia with a moderate diffuse lichenoid interface inflammatory infiltrate consisting of lymphocytes and plasma cells. There was also focal hydropic degeneration of the epidermal basal cell layer, pigmentary incontinence, and mixed orthokeratotic and parakeratotic hyperkeratosis. In all 4 dogs, the pinnal lesions were unilateral and asymptomatic. Complete surgical excision was curative.

Characterization of lichenoid-psoriasiform dermatosis of springer spaniels.

Three unrelated Springer Spaniels were examined because of chronic dermatitis. Their ages at onset of clinical signs were 4, 5, and 18 months. The initial lesions consisted of erythematous papules and plaques, with corrugated surfaces in the ear canal and in the inguinal area. Later, papules, scale, and adherent keratin mounds developed inside the ear, in the inguinal area, around the mouth, eyes, and anus, and occasionally on the thoracic wall and the limbs. In one case, the nose was involved and there was accompanying depigmentation. The disease waxed and waned for the 10-month, 18-month and 3-year periods of observation, with various treatments proving unsuccessful. Corticosteroids at high doses and antibiotics appeared to mitigate the severity of the disease. Histopathologic interpretation enabled classification of the disease process within both psoriasiform and lichenoid tissue reactions. In view of the apparent breed predisposition and the gross and microscopic appearance of the lesions, it was proposed that the name for this disease be lichenoid-psoriasiform dermatosis of Springer Spaniels. This disease would be clinically classified as seborrhea and could be differentiated within this group by the presence of erythematous papules and plaques along with accurate histologic assessment.