Infections of the Larynx and Epiglottis Laryngitis Laryngitis is defined as any inflammatory process involving the larynx and can be caused by a variety of infectious and noninfectious processes. The vast majority of laryngitis cases seen in clinical practice in developed countries are acute. Acute laryngitis is a common syndrome caused predominantly by the same viruses responsible for many other URIs. In fact, most cases of acute laryngitis occur in the setting of a viral URI. Etiology Nearly all major respiratory viruses have been implicated in acute viral laryngitis, including rhinovirus, influenza virus, parainfluenza virus, adenovirus, coxsackievirus, coronavirus, and RSV. . | Chapter 031. Pharyngitis Sinusitis Otitis and Other Upper Respiratory Tract Infections Part 12 Infections of the Larynx and Epiglottis Laryngitis Laryngitis is defined as any inflammatory process involving the larynx and can be caused by a variety of infectious and noninfectious processes. The vast majority of laryngitis cases seen in clinical practice in developed countries are acute. Acute laryngitis is a common syndrome caused predominantly by the same viruses responsible for many other URIs. In fact most cases of acute laryngitis occur in the setting of a viral URI. Etiology Nearly all major respiratory viruses have been implicated in acute viral laryngitis including rhinovirus influenza virus parainfluenza virus adenovirus coxsackievirus coronavirus and RSV. Acute laryngitis can also be associated with acute bacterial respiratory infections such as those caused by group A Streptococcus or C. diphtheriae although diphtheria has been all but eliminated in the United States . Another bacterial pathogen thought to play a role albeit unclear in the pathogenesis of acute laryngitis is M. catarrhalis which has been recovered on nasopharyngeal culture from a significant percentage of people with acute laryngitis. Chronic laryngitis of infectious etiology is much less common in developed than in developing countries. Laryngitis due to Mycobacterium tuberculosis is often difficult to distinguish from laryngeal cancer in part because of the frequent absence of signs symptoms and radiographic findings typical of pulmonary disease. Histoplasma and Blastomyces may cause laryngitis often as a complication of systemic infection. Candida species can cause laryngitis as well often in association with thrush or esophagitis and particularly in immunosuppressed patients. Rare cases of chronic laryngitis are due to Coccidioides and Cryptococcus. Clinical Manifestations Laryngitis is characterized by hoarseness and can also be associated with reduced vocal pitch or aphonia. As acute