SUBEPIDERMAL BULLOUS DERMATOSIS DUE TO TOPICAL CORTICOSTEROID-THERAPYIN DOGS

Six adult dogs were presented with an unusual bullous dermatosis affec ting the glabrous skin of the ventral abdomen and medial thighs. Clini cally, flaccid bullae were accompanied by erythema, ulceration, haemor rhage and hyperpigmentation in four of six dogs; the remaining two dog s had thin skin without grossly apparent bullae. Histologically, subep idermal bullae and clefting, vascular proliferation and dilatation (ph lebectasia), and alteration in the density and staining of superficial dermal collagen were seen in all dogs. In all cases, corticosteroid-c ontaining topical products had been applied to the affected areas prio r to the development of the dermatosis; skin lesions resolved when top ical corticosteroids were withdrawn. Follow-up biopsy of three dogs sh owed resolution of the previously abnormal collagen and subepidermal c lefting. Residual lesions included phlebectasia, comedones and hyperpi gmentation. The authors postulate that subepidermal clefting was due t o local, corticosteroid-induced skin fragility. This is the first repo rt, to our knowledge, of bullous skin disease in dogs resulting from t opical corticosteroid therapy.