• Ear, nose, throat involvement (90-95%)
o It is the most common involvement in this disease.
o The most common finding in this region is sinusitis (erosive sinusitis and bloody purulent nasal discharge).
o Subglottic tracheal stenosis, otitis media, hearing loss etc. can be seen.
o Nasal septum perforation and subsequent saddle nose deformity may develop.
• Lung involvement (85-90%)
o Patients may present with cough, bloody sputum (alveolar hemorrhage - pulmonary capillaritis) and shortness of breath
o The most common finding is pulmonary infiltrates.
o Pulmonary infiltrates typically appear as nodular and cavitary.
• Kidney involvement (77%)
o Renal involvement dominates the clinical picture. Kidney disease is responsible for the majority of mortality.
o Renal biopsies show focal segmental necrotizing glomerulonephritis and rapidly progresses to crescentic glomerulonephritis if left untreated.
• Eye involvement
o Scleritis and ulcerative keratitis are the most dangerous eye lesions.
o Proptosis due to orbital mass (pseudotumor) may be seen.
• Nervous system
o Granulomatous inflammation in the meninges and chronic meningitis are the most common CNS findings.
Laboratory Findings
• ANCA
o cANCA(anti-proteinase 3) is approximately 95% specific for the diagnosis of GPA.
o In some cases, ANCA is negative. Therefore, being ANCA negative does not rule out GPA.
Diagnosis
• Diagnosis is made by observing necrotizing granulomatous vasculitis in tissue biopsy in a patient with a suitable clinic.
• Necrotizing granulomatous vasculitis is invariably seen on biopsy in lung involvement. (Therefore, the most diagnostic biopsy specimen is the lung)
• In the kidney, granuloma formation is rare.
Treatment
• The combination of high-dose steroid and cyclophosphamide is quite effective.
• Rituximab can also be used as an alternative to cyclophosphamide.
• In severe cases, plasmapheresis can be performed.
• Cotrimoxazole can be used in isolated upper respiratory tract involvement (it is ineffective in other major organ involvement)