Spirochetes play a role in ulcerative gingivitis and periodontitis. Actinomyces israelii can produce chronic burrowing infections of the gums and jaw, occasionally with secondary involvement of the respiratory tract. Fungal diseases, such as histoplasmosis and South American blastomycosis, and parasitic diseases, such as leishmaniasis, may involve the upper respiratory tract. Although rare in the United States, rhinoscleroma can occur in immigrants from developing countries or in HIV-infected persons. Many bacterial species have been implicated in a variety of dental infections.
Dental infection is the leading cause of necrotizing cervical fasciitis.
Many noninfectious processes in these regions can produce symptoms that mimic infection. Aphthous stomatitis may be the most common example. Drug reactions and primary dermatologic diseases cause oral and pharyngeal ulcerations. Vasculitis, carcinomas, lymphomas, and sarcoidosis of the upper airway can also mimic infection. Even subacute thyroiditis, which may produce fever and referred pain, may be mistaken for pharyngitis or otitis.