Acute bacterial suppurative parotitis, also called acute parotitis, sialadenitis, or sialoadenitis, is an inflammatory and infectious process of the parotid gland. The parotid gland is the major salivary gland in humans and is the most common salivary gland affected by the inflammatory process.

Common risk factors include old age, malnutrition, poor oral hygiene, and dehydration as well as the use of medications that reduce salivary flow, such as antihistamines, tranquilizers, and diuretics. Other predisposing factors include the presence of a tracheostomy tube, foreign body obstruction or trauma to the duct, an oral cavity neoplasm, prior radiation therapy, and cystic fibrosis (sialectasis). Reduced salivary flow / salivary stasis permits indigenous flora to ascend, which can lead to suppurative parotitis. Suppurative parotitis can also originate from a septic focus in the oral cavity caused by, eg, chronic tonsillitis or dental infection.

Commonly involved organisms are often polymicrobial mixed oral aerobes and anaerobes, with Staphylococcus aureus as the predominant isolate. Other gram-positive organisms include Streptococcus pneumoniae, Streptococcus pyogenes, and Haemophilus influenzae. Anaerobic oral flora are considered ubiquitous components of pathogens, and include Prevotella spp., Peptostreptococcus spp., Bacteroides spp., Fusobacterium spp., and Actinomyces spp. Less frequently reported organisms include Escherichia coli, Klebsiella pneumoniae, and Eikenella corrodens. Few cases of Mycobacterium tuberculosis, Mycobacterium scrofulaceum, Treponema pallidum (syphilis), and Candida albicans have been reported.

Suppurative parotitis primarily occurs in elderly patients with systemic illness or who have recently undergone surgery, although it can occur at any age. Neonatal suppurative parotitis is a rare disease. Only a few cases are reported in the literature.

When complicated by parotid abscess, parotitis is a potentially life-threatening condition. Other complications include osteomyelitis of the adjacent facial bones, septic thrombophlebitis of jugular vein (Lemierre's syndrome), facial nerve dysfunction, trismus, and extension of infection into deep neck space with respiratory compromise, which is often caused by infection of the carotid sheath. These complications can be fatal if not treated.

Fine needle aspiration may help determine whether surgical drainage is needed in acute suppurative parotitis.

Related topics: Parotitis, Mumps