A 30-year-old quadriplegic man presents to the emergency room with fever, dyspnea, and a cough. He has a chronic indwelling Foley catheter. Recurrent urinary tract infections have been a problem for a number of years. He has been on therapy to suppress the urinary tract infections. On examination, the patient has a temperature of 38°C (100.4°F), HR 88, and BP 126/76. Mild wheezing is audible over both lungs. A diffuse erythematous rash is noted. The chest x-ray shows diffuse alveolar infiltrates. The CBC reveals a WBC of 13,500, with 50% segmented cells, 30% lymphocytes, and 20% eosinophils. Which of the following is the most likely diagnosis?
A. Sepsis with ARDS secondary to urinary tract infectionClues to this diagnosis are recurrent urinary tract infections and the use of suppressive therapy to control these infections. Nitrofurantoin is commonly used for this purpose. Nitrofurantoin can cause an acute hypersensitivity pneumonitis. This condition can progress to a chronic alveolitis with pulmonary fibrosis. The presenting symptoms are fever, chills, cough, and bronchospasm. In addition, the patient may experience arthralgias, myalgias, and an erythematous rash. The chest x-ray will show interstitial or alveolar infiltrates. CBC often shows leukocytosis with a high percentage of eosinophils. The treatment is to discontinue the nitrofurantoin, and to begin corticosteroids. Sepsis secondary to a urinary tract infection and healthcare-related pneumonia might be considered. However, these would not present with a diffuse erythroderma or eosinophilia. Acute bacterial infections cause a neutrophilic leukocytosis; eosinophils are usually undetectable owing to the stress effect of catecholamines and cortisol. COPD rarely presents in a 30-year-old. Lymphocytic interstitial pneumonia is a rare disease and would cause interstitial rather than alveolar infiltrates. Lung biopsy to establish the diagnosis of an interstitial lung disease would be considered only after the potentially offending drug had been discontinued.