Pharyngotonsillitis (PT) is an inflammation of the pharynx and tonsils characterized by the presence of increased pharyngeal and tonsillar redness and finding of an exudate, ulceration, or a membrane covering the tonsils. Because the pharynx is served by lymphoid tissues of the Waldeyer ring, an infection can spread to include various parts of the ring such as the nasopharynx, uvula, soft palate, tonsils, adenoids, and the cervical lymph glands. Based on the extent of the infection, it can be described as pharyngitis, tonsillitis, tonsillopharyngitis, or nasopharyngitis. The duration of any of these illnesses can be acute, subacute, chronic, or recurrent.

Etiology

The diagnosis of PT generally requires the consideration of group A β-hemolytic streptococci (GABHS) infection. However, other bacteria, viruses, and other infections and noninfectious causes should be considered. Recognition of the cause and choice of appropriate therapy are of utmost importance in assuring rapid recovery and preventing complications.

Table 4.1 lists the different causative agents and their characteristic clinical features. The occurrence of a certain etiologic agent depends on multiple variables that include environmental conditions (season, geographic location, exposure) and individual variables (age, host resistance, and immunity). The most prevalent agents accounting for PT are GABHS, adenovirus, influenza virus, parainfluenza virus, Epstein–Barr virus (EBV), and enterovirus. However, the exact etiology is generally not determined and the role of some potential pathogens is not certain.

Recent studies suggested that interactions between various organisms, including GABHS, other aerobic and anaerobic bacteria, and viruses, may occur during PT. Some of these interactions may be synergistic (i.e., between EBV and anaerobic bacteria), thus enhancing the virulence of some pathogens, whereas others may be antagonistic (i.e., between GABHS and certain “interfering” -hemolytic streptococci). Furthermore, β-lactamase-producing bacteria (BLPB) can protect themselves as well as other bacteria from β-lactam antibiotics.