Snapshot A 45-year-old woman presents to the physician's office for a painful and blistering rash. She reports having a 1-month history of nonhealing ulcers in her mouth, which she previously attributed to stress. However, she reports new ulcers in her mouth and new easily-ruptured blisters on her skin. Approximately 6 weeks ago, she reported starting a new drug, captopril, for management of her hypertension. On physical exam, she has dozens of flaccid bullae and erosions on her trunk and extremities; she has 3 ulcers along her buccal mucosa. She is started on systemic steroids and captopril is discontinued. Introduction Clinical definition pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterized by painful mucocutaneous lesions Epidemiology demographics most common in those of Mediterranean or Jewish descent 40-60 years of age Pathogenesis autoantibodies (IgG) against desmoglein, a component of desmosome recall that desmosomes connect keratinocytes in the skin type II hypersensitivity reaction this disrupts keratinocyte adhesion and causes separation of epidermis Associated conditions drug use thiols penicillamine benzylpenicillin captopril cephalosporin thymoma myasthenia gravis systemic lupus erythematosus Prognosis without treatment, prognosis is poor 75% mortality at 1 year with treatment, prognosis is improved 10% mortality at 1 year Presentation Symptoms nonhealing and nonscarring ulcers persisting for at least 1 month extremely painful progressive development of blisters from mouth to the rest of the body 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 (mucosal involvement) anti-desmoglein 1 (mucocutaneous involvement) Histology acantholysis separation of epidermal cells intraepidermal blister direct immunofluorescence intercellular deposition of IgG or C3 in a 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