Introduction: Systemic vasculitic syndromes are rare in children. Polyarteritis nodosa (PAN) is characterized by necrotizing arteritis of small and medium arteries in various organs. Infantile polyarteritis nodosa typically presents in children under 2 years of age as a multisystem disease with signs of congestive heart failure or renal failure. We present a case of hypoxemic respiratory failure as the primary presentation of polyarteritis nodosa.
Case Presentation: A 16-month-old Filipino male presented to an outlying hospital with a 3 day history of congestion, cough and fever. A CXR revealed bilateral pulmonary infiltrates. The patient was admitted and was started on Biaxon, Claforan and vancomycin. On hospital day 4, the patient had increasing respiratory distress with hypoxemia, tachypnea and retractions. CXR revealed an increase in bilateral pulmonary infiltrates and a right-sided pleural effusion. A thoracostomy was performed and the patient was placed on Albuterol and Solumedrol. He was discharged home 3 days later on room air and tapering dose of steroids.
Ten days later, the patient developed a temperature of 103 [degrees] F, tachypnea, retractions and an [O.sub.2] saturation of 86% on room air. He was found positive for respiratory syncytial virus and started on Ribaviron. His CXR was unchanged from his prior admission with bilateral pulmonary infiltrates. The patient developed hypertension and had a progressive oxygen requirement at which point he was intubated. He was managed on conventional mechanical ventilation with maximal settings without improvement for 36 hours. At this point, an open lung biopsy was performed and he was transferred to our institution for further management. Physical exam was unremarkable with the exception of his lung exam which had a prolonged respiratory phase. The patient was placed on high frequency oscillating ventilator (HFOV) with 100% FiO2; MAP 20: delta P 40: Hz 8 with an ABG 7.42/37/67/25/0/93%. Antibiotics were changed empirically to Imipenem and Ceftriaxone. Solumedrol was started at 2 mg/kg/dose. A bronchial alveolar lavage (BAL) was performed and sent for acid fast bacilli (AFB), mycoplasma, pertussis, coccidiomycoses, and legionella, which were all negative. IgG and IgM levels were elevated; ESR 15, CRP 5.1, ANCA neg; ANA neg. An echocardiogram demonstrated normal function and no pericardial effusion. Lung biopsy demonstrated immune-mediated vasculitis affecting small pulmonary arteries and patchy interstitial infiltrates with possible microvasculitis all consistent with PAN. Features were not consistent with Wegner's granulomatosis and there was no histologic evidence for Churg-Strauss vasculitis or sarcoid. The patient was begun on Imuran and high dose steroids. He was weaned to extubate within 36 hours and was discharged home 3 days post-extubation. After 3 months of treatment, his medications were weaned at which time he began having tachypnea and infiltrates on CXR. His steroids were increased and his symptoms resolved.
Discussion: The vasculitides in children include Kawasaki's and Henoch-Schonlein purpura (HSP) which are common, and only rarely include PAN and Wegener's granulomatosis. Clinical features that suggest a vasculitic syndrome include fever of unknown origin, palpable purpura, dermal necrosis, unexplained arthritis and unexplained pulmonary, cardiovascular or renal disease. These features are seen in association with leukocytosis, eosinophilia, hypocomplementemia, circulating immune complexes and increased ESR and CRP. Kawasaki's has a classic clinical presentation and may cause coronary aneurysms none of which were present in our patient. HSP affects arterioles and venules through IgA deposits in the skin, GI tract, kidney or joints. Wegener's affects small arteries and veins in the lung and kidney and is differentiated pathologically by the presence of granuloma formation and parenchymal necrosis, neither of which were identified on lung biopsy in our patient. PAN in children does not typically present primarily with pulmonary symptoms. However, Matusumoto et al. presented 10 pathologic cases of PAN where 70% of the autopsy specimens demonstrated lung involvement suggesting that pulmonary involvement in PAN may be more common than has previously been recognized.
Conclusion: The vasculitides, including PAN, should be included in a differential diagnoses of childhood hypoxemic respiratory failure.
 Matsumoto T, et al. The lung in polyarteritis nodosa: a pathologic study of 10 cases. Human Path 1993; 24(7):717-724
Suresh Havalad, MD, M. Vellaichamy, MD, I. Akhtar, MD, E. Bello, MD--Lutheran General Children's Hospital, Park Ridge, IL
COPYRIGHT 1999 American College of Chest Physicians
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