What is the most likely diagnosis? A 59-year-old woman was recently admitted to the hospital because of oral ulcers and diffuse crusted, denuded, erythematous plaques on her torso and upper ARMS (see image). She has tested positive for anti-epithelial cell antibodies.

Pemphigus vulgaris

The correct answer is E. This patient has pemphigus vulgaris, a potentially fatal autoimmune disorder characterized by easily ruptured superficial vesicles that often crust and erode. It is thought to be due to IgG antibody against epidermal cell membrane. Lesions of the oral mucosa are characteristic of pemphigus vulgaris Answer A is incorrect. In bullous pemphigoid, patients have skin vesicles that are fi lled with a clear fluid; however, unlike pemphigus vulgaris, patients have IgG antibody against epidermal basement membrane. The bullae generally heal without scarring and do not rupture as easily as do the vesicles of pemphigus vulgaris. Oral mucosal lesions are found in 10% 40% of patients with bullous pemphigoid Answer B is incorrect. Eczema is characterized by itchy, red papulovesicular skin that, through excessive scratching, can become denuded and prone to bacterial superinfection Answer C is incorrect. Erythema multiforme is characterized by a combination of macules, papules, vesicles, bullae, and target lesions (spreading halos of erythema and central clearing) that often symmetrically affect the extremities Answer D is incorrect. Impetigo is a common skin infection caused by staphylococci or streptococci. It often presents as shallow skin erosions that have honey-crust-appearing edges.