Pemphigus foliaceus in cats

Abstract

Pemphigus foliaceus is the most common autoimmune skin disease in cats. Autoantibodies attack and destroy desmosomes, the structures connecting one keratinocyte to the other, causing what is clinically recognised as a pustular dermatitis. The target autoantigen within the desmosome is unknown in cats. The disease occurs more frequently in middle-aged cats and involves predominantly the pinnae, head and feet, including the claw folds. Clinical lesions include superficial erosions and honey-coloured crusts, alopecia, scaling and caseous material that can be expressed out of the claw folds, while pustules are rarely appreciated. Cats may be systemically ill. Diagnosis requires cytology and histopathology, as well as ruling out dermatophytosis and bacterial infections. Treatment is based on glucocorticoid monotherapy. Other immunomodulatory drugs, such as ciclosporin or chlorambucil, may be added to reduce the glucocorticoid requirement. The prognosis is good, but regular checks-ups are mandatory because of potential relapse and possible adverse effects of the drugs used.