Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is a multisystem disease of unknown etiology characterized by vasculitis and necrotizing granulomatous inflammation of the small arteries and veins. Classic generalized GPA is a triad of necrotizing granulomas of the upper and lower respiratory tract, systemic necrotizing small vessel granulomatous vasculitis, and glomerulonephritis (usually focal segmental). GPA most often occurs in patients in middle age and of Northern European descent (80%-90% of cases), but cases have been reported in children and older adults.

The disease typically presents with upper airway disease and nonspecific complaints such as malaise, arthralgias, fever, and weight loss. Respiratory tract symptoms include sinusitis, otitis media, rhinorrhea, cough, sputum production, chest pain, dyspnea, and hemoptysis. Oral lesions can be seen with any of the clinical presentations of GPA and consist of ulcerations and/or "strawberry" gingivitis.

Ocular involvement occurs in 30%-50% of patients with GPA and can occur without systemic manifestations. There can be orbital, retinal, nasolacrimal, and anterior segment involvement. The most common findings are scleritis and orbital disease. Ocular manifestations of GPA result from granulomatous sinusitis infiltrating the orbit, causing nasolacrimal duct obstruction and proptosis, putting increased pressure on the intraocular muscles and optic nerve. Many patients complain of decreased vision. Vision may also be lost, as proptosis can lead to exposure keratopathy and corneal ulceration. There may also be a focal vasculitis, such as conjunctivitis, episcleritis, scleritis, uveitis, or granulomatous vasculitis of the retina and optic nerve.

The disease presents variably on a continuum from limited involvement (which may remain limited for variable periods of time) to a more generalized form with involvement of the upper and lower respiratory tract, kidney, skin, and other organs. Untreated, the generalized form is fatal in less than 2 years; however, with the advent of cytotoxic therapy, long-term remissions are possible in more than 90% of patients.

Complications of GPA include pericarditis, coronary arteritis, myocardial infarction, pancarditis, granulomatous valvulitis, mononeuritis multiplex, and polyneuritis. Laryngotracheal stenosis with stridor can be a complication of GPA and initially may be misdiagnosed as asthma.