Eosinophilic Pneumonia in a Patient with Ulcerative Colitis.

We present the case of 16-year-old woman with a 2-month history of ulcerative colitis who presented with cough, fever, dyspnea on exertion, and nasal congestion. Computed tomography of the chest demonstrated peripheral alveolar opacities with relative sparing of the central portions of the lungs. The clinical and radiologic findings raised the suspicion of eosinophilic pneumonia, possibly drug-related. The patient had recently been started on a trial of Mesalamine (5-aminosalicylic acid or 5-ASA) for treatment of her ulcerative colitis 2 months ago. The patient's condition improved after discontinuation of mesalamine and treatment with prednisone. The clinical course and radiologic features supported the presumptive diagnosis of Mesalamine-induced eosinophilic pneumonia.

Case Report

The patient is a 16 year-old female who was diagnosed with ulcerative colitis two months earlier. Prior to this diagnosis she had no significant medical history and denied having any allergies. The initial treatment of her ulcerative colitis included a trial of Mesalamine. Within a month after diagnosis, the patient presented to the emergency department complaining of a two-week history of cough, nasal congestion, dyspnea on exertion, sore throat, headache, fever, chest and neck pain. Her work up included a lumbar puncture, chest x-ray, and Epstein-Barr virus titers, all of which were negative. As a result the patient was discharged home with non-specific diagnoses of headache and dehydration. On present admission, the patient complains of worsening symptoms. Her review of systems was positive for a seven-pound weight loss, night sweats, and chills. Regarding her ulcerative colitis, she stated that she continued to have diarrhea and abdominal pain but these symptoms were improving. Her vitals on admission were: Temperature of 101.4 degrees Farenheit, heart rate of 86 beats per minute, respiratory rate of 20 breaths per minute, blood pressure of 112/75 mm Hg, height of 5 feet and 1/2 inches, and weight of 94 lbs. Physical examination was significant for decreased breath sounds bilaterally. Laboratory studies revealed an elevated white blood cell count with increased eosinophils and a microcytic anemia. Her sedimentation rate was elevated and she had a positive perinuclear staining anti-neutrophil cytoplasmic antibody (p-ANCA). Additional lab work was negative for: rheumatoid factor, angiotensin-1 converting enzyme (ACE), and human immunodeficiency virus (HIV).

Radiography of the chest showed bilateral, peripheral upper lobe opacities with air bronchograms and possible adenopathy (Fig. 1). CT of the chest was obtained for further evaluation of the peripheral lung parenchymal process seen on chest X-ray (Fig. 2). The chest CT also demonstrated extensive peripheral alveolar opacities in the mid and upper lungs bilaterally which were fairly symmetrical with relative sparing of the central portion of both lungs and the lung bases. There was no significant hilar adenopathy. Based on the patient's symptomatic presentation, laboratory findings, and her radiographic pattern of peripheral parenchymal consolidation, the patient was diagnosed with eosinophilic pneumonia.

Figure 1

16-year-old woman with presumptive Mesalamine-induced eosinophilic pneumonia. PA and lateral chest images at presentation show bilateral peripheral areas of consolidation with an upper predominance. Slight prominence of the right hilum is apparent which represented lung disease within the medial portion of the right lung.

Figure 2

16-year-old woman with presumptive Mesalamine-induced eosinophilic pneumonia. At time of presentation, axial contrast enhanced chest CT at the level just below the carina shows bilateral peripherally located areas of consolidation with air-bronchograms. The more central lung areas are free of the process.

The patient was taken off Mesalamine due to suspected Mesalamine-induced eosinophilic pneumonia and started on prednisone plus 6-mercaptopurine for her ulcerative colitis. In less than a week the patient showed significant symptomatic improvement with corresponding improvement of chest X-ray and CT scan. Given the fairly rapid improvement of these peripheral opacities, an eosinophilic-related process was felt to be most likely. In 8 days, her white blood cell count started to normalize and the eosinophilia had resolved. The patient was discharged home in stable condition.

Discussion

Mesalamine (5-aminosalicylic acid or 5-ASA) is widely used as the maintenance therapy for ulcerative colitis. Although very rare, Mesalamine-induced pulmonary toxicity has been documented in the literature [1, 2, 3, 4, 5, 6, 7, 8], with eosinophilic pneumonia as the most common presentation [2]. Clinical manifestations can occur anywhere from 2 to 6 months after initiating Mesalamine treatment. Patients commonly present with dyspnea on exertion, fever, chest pain, and cough [2, 3, 4]. Patients' laboratory findings may include eosinophilia and a positive perinuclear staining anti-neutrophilic cytoplasmic antibody (positive p-ANCA typically found in patients with ulcerative colitis) [2, 5]. The sedimentation rate was elevated in our case, but it can be normal [3]. Radiographic findings of Mesalamine-induced lung toxicity are reported to be nonspecific with findings that include interstitial opacities, peripheral or diffuse acinar infiltrates, and pleural effusions [3, 4]. Our patient exhibited mainly peripheral lung opacities without a pleural effusion. Prompt resolution of lung disease after cessation of mesalamine, with or without steroids is the usual course [1, 3, 4, 6, 7, 8]. The rapid improvement in clinical and radiographic findings in the above patient after the discontinuation of Mesalamine strongly supports the diagnosis of mesalamine-induced eosinophilic pneumonia [1, 6, 8].

16-year-old woman with presumptive Mesalamine-induced eosinophilic pneumonia. A, At time of presentation, 2D coronal reconstruction of the contrast-enhanced chest CT emphasizes the peripheral location of the lung opacities. B Nine days after discontinuation of mesalamine and onset of steroid therapy, 2D coronal reconstruction chest CT shows marked improvement.