Drug‐induced pemphigoid: a review of the literature

Bullous pemphigoid is an acquired autoimmune disease that is characterized by subepidermal blistering and affects mainly the elderly. The pathogenesis of the condition has not yet been fully elucidated, but it is widely accepted that a strong correlation with various medications may exist. In reality, more than 50 different drugs have been associated with the appearance of bullous pemphigoid and as new therapies emerge, this number is very likely to increase. A number of pathogenetic mechanisms have been proposed in the past. It is true that a delicate immunological balance is disturbed in all patients with the disease. The variable effects that may be exhibited by the use of biological drugs could shed some light in this complex immunological behaviour. At the same time, drug-induced bullous pemphigoid is difficult to differentially diagnose from its idiopathic counterpart, as the clinical picture and histopathological findings in both conditions may only have subtle differences. Patients who present with bullous pemphigoid and receive multiple regimens should always be suspected of suffering from the drug-induced variant of the condition. This possibility must be considered, as after the withdrawal of the suspect medication most patients respond rapidly to treatment and do not experience relapses.