Tonsillitis: Inflammation of the tonsils, especially the PALATINE TONSILS but the ADENOIDS (pharyngeal tonsils) and lingual tonsils may also be involved. Tonsillitis usually is caused by bacterial infection. Tonsillitis may be acute, chronic, or recurrent.Tonsillectomy: Surgical removal of a tonsil or tonsils. (Dorland, 28th ed)Peritonsillar Abscess: An accumulation of purulent material in the area between the PALATINE TONSIL and its capsule.Palatine Tonsil: A round-to-oval mass of lymphoid tissue embedded in the lateral wall of the PHARYNX. There is one on each side of the oropharynx in the fauces between the anterior and posterior pillars of the SOFT PALATE.Adenoids: A collection of lymphoid nodules on the posterior wall and roof of the NASOPHARYNX.Pharyngitis: Inflammation of the throat (PHARYNX).Tonsillar Neoplasms: Tumors or cancer of the PALATINE TONSIL.Prevotella intermedia: A species of gram-negative, anaerobic, rod-shaped bacteria originally classified within the BACTEROIDES genus. This bacterium is a common commensal in the gingival crevice and is often isolated from cases of gingivitis and other purulent lesions related to the mouth.Geotrichosis: Infection due to the fungus Geotrichum.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Fusobacterium nucleatum: A species of gram-negative, anaerobic, rod-shaped bacteria isolated from the gingival margin and sulcus and from infections of the upper respiratory tract and pleural cavity.Recurrence: The return of a sign, symptom, or disease after a remission.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.