Aggregatibacter actinomycetemcomitans Causing Empyema Necessitans and Pyomyositis in an Immunocompetent Patient

Nora Homsi,Rajendra Kapila

doi:10.7759/cureus.9454

Abstract

Empyema necessitans is a relatively rare clinical entity in which the empyema extends through the parietal pleura into the adjacent soft tissue and musculature of the chest wall. It usually occurs due to inadequate treatment of a primary lung infection. Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans is a facultative anaerobic gram-negative coccobacillus that is part of the normal oral flora. Infections due to this organism usually result from aspiration in conjunction with dental disease or trauma to the oral mucosa resulting in pneumonia or empyema. It often coinfects with Actinomyces and is known to cause empyema necessitans. Cases of monomicrobial empyema necessitans due to Aggregatibacter actinomycetemcomitans in adults have rarely been reported with four such publications found on review of the literature. We present a patient with severe periodontitis who developed empyema necessitans due to Aggregatibacter actinomycetemcomitans likely from aspiration complicated by pyomyositis of the right triceps brachii and a left posterior thigh abscess.

Highlights

Empyema necessitans, a rare complication of empyema, is a pyogenic infection extending directly from the pleural cavity into the overlying subcutaneous tissue and causes infection in surrounding structures, such as the chest wall, mediastinum, pericardium, esophagus, and retroperitoneum [1,2]
Several causative pathogens have been reported in the literature and include Mycobacterium tuberculosis, Streptococcus pneumoniae, Staphylococcus aureus, Pseudomonas, Actinomyces, and others [1,2,3,4]
We present a patient who developed empyema necessitans due to Aggregatibacter actinomycetemcomitans likely from aspiration in the setting of periodontitis

Summary

Introduction

A rare complication of empyema, is a pyogenic infection extending directly from the pleural cavity into the overlying subcutaneous tissue and causes infection in surrounding structures, such as the chest wall, mediastinum, pericardium, esophagus, and retroperitoneum [1,2]. We present a patient who developed empyema necessitans due to Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans likely from aspiration in the setting of periodontitis His infection was complicated by pyomyositis of the right triceps brachii and a left posterior thigh abscess. The infectious diseases team was not consulted at that time Two months later, he presented again to our hospital with a painful and erythematous right upper chest wall mass that had been enlarging over the past two weeks and was associated with subjective fevers and a nonproductive cough. Review of the CT scan of his right upper extremity from two months earlier revealed a partially seen right lung consolidation that had not been previously reported, suggesting a pulmonary origin of infection In light of his severe dental disease, aspiration was most likely the precipitating event. On outpatient follow-up two months after discharge, he remained infection-free with normalization of his acute phase reactants

Discussion

Conclusions

Disclosures