Stomatitis
Stomatitis is an inflammation of the mucous membranes of the oral cavity. Herpes simplex virus is the primary agent of this disease, in which multiple ulcerative lesions are seen on the oral mucosa. These lesions are painful and can be found in the mouth and in the oropharynx. Herpetic infections of the oral cavity are prevalent among immunosuppressed patients.
Thrush
Candida spp. can also invade the oral mucosa. Immunosuppressed patients, including very young infants, may develop oral candidiasis, called thrush. Oral thrush can extend to produce pharyngitis or esophagitis, a common finding in patients with acquired immunodeficiency syn drome and in other immunosuppressed patients. Thrush is suspected if whitish patches of exudate on an area of inflammation are observed on the buccal (cheek) mucosa, tongue, or oropharynx. Oral mucositis or pharyngitis in the granulocytopenic patient may be caused by Enterobacteriaceae, S. aureus, or Candida spp. and is manifested by erythema, sore throat, and possibly exudate or ulceration.
Periodontal Infections
Types. The three dental problems that may require culture and identification in a clinical laboratory include (1) root canal infections, with or without periapical abscess; (2) orofacial odontogenic infections, with or without osteomyelitis (inflammation of a bone) in the jaw; and (3) perimandibular space infections. Oral bacteria are clearly important in other dental processes, such as caries (destruction of the mineralized tissues of the tooth; a cavity), periodontal (tissues in, around, and supporting the tooth) disease, and localized juvenile periodontitis, but clinical laboratories are not involved in culturing in such cases.
Etiologic Agents. The bacteriology is similar in all of these infections and involves primarily anaerobic bacteria and streptococci except for perimandibular space infections, which may also involve staphylococci and Eikenella corrodens in about 15% of patients. The streptococci are microaerobic or facultative and are usually alpha-hemolytic (particularly the Streptococcus anginosus group); they are usually found in 20% to 30% of dental infections.
Members of the Bacteroides fragilis group are found in root canal infections, orofacial odontogenic infections, and bacteremia secondary to dental extraction in 5% to 10% of patients. Anaerobic cocci (both Peptostreptococcus and Veillonella), pigmented Prevotella and Porphyromonas, the Prevotella oralis group, and Fusobacterium are found in about 20% to 50% of the three conditions mentioned, as well as in postextraction bacteremia. Infection with Actinomyces israelii may complicate oral surgery.
Salivary Gland Infections
Acute suppurative parotitis (inflammation of the salivary glands located under the cheek in front of and below the external ear) is seen in very ill patients, especially those who are dehydrated, malnourished, elderly, or recovering from surgery. It is associated with painful, tender swelling of the parotid gland; purulent drainage may be evident at the opening of the duct of the gland in the mouth. Staphylococcus aureus is the major pathogen but on occasion Enterobacteriaceae, other gram-negative bacilli, and oral anaerobes may play a role in infection. A chronic bacterial parotitis has been described involving Staphylococcus aureus. Less often, other salivary glands may be involved with a bacterial infection, usually because of ductal obstruction.
The mumps virus is traditionally the major viral agent involved in parotitis; however, since the advent of child hood vaccination, infection with mumps virus is rarely diagnosed. Influenza virus and enteroviruses may also cause this syndrome. Viral parotitis is typically diagnosed using serology. Infrequently, Mycobacterium tuberculosis may involve the parotid gland in conjunction with pulmonary tuberculosis.
