A 19-year-old man with a history of recent-onset asthma presents with chest pain, intermittent claudication and respiratory distress that is unresponsive to bronchodilators and antibiotics. Physical examination reveals mild hypeension (blood pressure = 150/100 mm Hg), bilateral wheezing and numerous purpuric skin lesions on the feet. Laboratory studies demonstrate that leukocytes are increased to 14,000/mL with increased eosinophils and platelets are increased to 450,000/mL. BUN is elevated to 30 mg/dL, and serum creatinine is elevated to 3.5 mg/dL. The serum antineutrophil cytoplasmic antibody test is positive. Urinalysis discloses 3+ proteinuria and RBCs. A renal biopsy demonstrates vasculitis of medium-sized aeries, accompanied by eosinophilia. Which of the following is the most likely diagnosis?
High-Yield Explanation
Churg-Strauss disease is an idiopathic, systemic, granulomatous disease of small- and medium-size aeries characterized by vasculitis of many organs, fluctuating eosinophilia and late-onset asthma. The majority of patients display antineutrophil cytoplasmic antibodies. The disease is also known as allergic granulomatosis and angiitis. Transbronchial lung biopsy shows granulomatous lesions in vascular and extravascular sites, accompanied by intense eosinophilia. The vasculitis histologically resembles the lesions of polyaeritis nodosa and Wegener granulomatosis, but these diseases do not typically present with an asthmatic syndrome.