Snapshot A 50-year-old man presents to his dermatologist for persistent blisters. He reports that the blisters started on his lips 3 weeks ago. He continues to develop new painful lesions on his lips but also on his trunk and arms. His dermatologist performs a punch biopsy. In the meantime, he is given topical steroids and an anesthetic for his mucosal lesions. Introduction Clinical definition pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterized by painful mucocutaneous lesions Associated conditions drug use thiols penicillamine benzylpenicillin captopril cephalosporin thymoma myasthenia gravis systemic lupus erythematosus Epidemiology Demographics most common in those of Mediterranean or Jewish descent 40-60 years of age ETIOLOGY Pathogenesis autoantibodies (IgG) against desmoglein, a component of the desmosome recall that desmosomes connect keratinocytes in the skin type II hypersensitivity reaction this disrupts keratinocyte adhesion and separation of the epidermis Presentation Symptoms nonhealing and nonscarring ulcers persisting for at least 1 month extremely painful progressive development of blisters from mouth to elsewhere Physical exam flaccid bullae that are easily ruptured clear exudate superficial erosions of skin (ruptured bullae) often on scalp, face, and trunk mucosal ulcers positive Nikolsky sign extension of blister or sloughing of skin with blunt pressure or lateral traction of skin Studies Labs auto-antibodies detected in serum with enzyme-linked immunosorbent assay (ELISA) anti-desmoglein 3 anti-desmoglein 1 Histology acantholysis separation of epidermal cells intraepidermal blister direct immunofluorescence intercellular deposition of IgG or C3 in net-like (reticular) pattern Differential Bullous pemphigoid less severe than PV does not affect mucous membranes negative Nikolsky sign Treatment Conservative wound care indications for all patients, to prevent secondary bacterial infection antiseptics anesthetic nebulizers for mucosal lesions potent topical steroids Medical systemic steroids indications mainstay treatment drugs prednisolone steroid-sparing immunosuppressants indications may be used concurrently with steroids for flares refractory to steroids drugs azathioprine mycophenolate mofetil Complications Skin and soft tissue bacterial infection of open lesions Risk of PV in newborn due to placental transfer of maternal autoantibodies Prognosis Without treatment, prognosis is poor 75% mortality at 1 year With treatment, prognosis is improved 10% mortality at 1 year