Case Presentation:

A 27–year–old African American male inmate with a history of occupational exposure to silica and fiberglass dust presented with an acute onset of dyspnea associated with left–sided pleuritic chest pain. He reported a 6–month history of mild dyspnea, nonproductive cough, night sweats and unintentional weight loss. He had a history of tobacco and marijuana abuse. On presentation he was afebrile and oxygen saturation was 97% on room air. Physical exam was remarkable only for diminished breath sounds in the left hemithorax with rales. A pneumothorax with bilateral infiltrates was noted on chest X–ray. A chest tube was subsequently placed for the pneumothorax. Laboratory studies revealed a mild leukocytosis with no left shift. An arterial blood gas analysis on 35% FiO2 showed a pH of 7.30, PaCO2 of 55 mmHg, PaO2 of 114 mmHg and SaO2 of 98%. HIV testing and other serological studies (including for rheumatologic diseases) were negative. A chest CT revealed bilateral peripheral ground glass infiltrates in both upper and lower lobes, bilateral subpleural interstitial thickening, and bronchiectasis in the left upper lobe. An open lung biopsy showed an interstitial pneumonitis with significant inflammation characterized by eosinophilic predominance. Noncaseating granulomas were also identified which demonstrated a polarizable foreign material suggestive of silica. Bronchoscopy and BAL were negative for infection. He was treated with intravenous steroids and had a gradual clinical recovery. His respiratory insufficiency and hypoxia significantly improved with resolution of infiltrates on repeated chest CT.

Discussion:

Chronic eosinophilic pneumonia (CEP) is a rare eosinophilic lung disease characterized by chronic and progressive nonspecific symptoms such as high fever, night sweats, weight loss, and severe dyspnea. Diagnosis is usually based on the association of chronic respiratory symptoms; alveolar and/or blood eosinophilia; characteristic peripheral pulmonary infiltrates on chest imaging; and exclusion of any known cause of eosinophilic lung disease. Histopathological findings include an interstitial and alveolar inflammation with accumulation of eosinophils and thickened alveolar walls, noncaseating granulomas occur in a minority of patients. Most of the cases are idiopathic. However drugs, toxins, and infectious causes have been associated with CEP. We report a case of CEP presenting with pneumothorax in a patient previously exposed to silica and fiberglass dust. This atypical presentation, to our knowledge, has not been described previously. CEP has a great response to corticosteroid treatment. The outcome for most patients is excellent despite frequent relapses and the occasional need for prolonged therapy.

Conclusions:

This case emphasizes the importance in combining clinical and histopathological findings along with an accurate occupational history to make the diagnosis of a rare disease.