Pemphigus vulgaris is an autoimmune bullous disorder involving the skin and 
sometimes the mucosa. Koebner's phenomenon is encountered when the typical 
features of a dermatosis are observed on a part of the skin previously subject 
to friction or trauma. A few cases of pemphigus vulgaris developing after damage 
to the skin and especially scars have been described. To the best of our 
knowledge, we report the first case where typical lesions of pemphigus vulgaris 
appeared simultaneously on a recent and an old scar as the sign of the 
reactivation of the disease.