Please note that the following is a general guideline only.
Epidemiology
50 - 60 years
male = female
parotid gland most common
associated with medically debilitated and postoperative patients
Aetiology
Systemic
-DM, hypothyroidism, renal failure, and
Local
reduced salivary flow-Medications/ Sjögren's syndrome
mechanical impairment - stenosis / sialolithiasis → more common in SMG ducts
Microbiology
most commonly -penicillin-resistant Staphylococcus aureus,
Streptococcus species,S pyogenes, S viridans, and S pneumoniae
Hemophilus influenzae
Anaerobic and gram-negative bacteria in acute suppurative sialadenitis
Pathophysiology
stasis of salivary flow secondary to dehydration
→ retrograde bacterial contamination of the salivary ducts from the oral cavity
→ suppurative infection of the gland parenchyma
Why parotid> SMG
parotid gland produces saliva that is mainly serous, as opposed to saliva from the SMG and SLGs that is primarily mucoid
serous saliva, unlike mucinous saliva, is deficient in lysosomes, IgA antibodies, and sialic acid, which have antimicrobial properties
Saliva of SMG and SLGs contains high molecular weight glycoproteins that competitively inhibit bacterial attachment to the epithelial cells of the salivary ducts
Clinical
systemic- fever, chills, and malaise
rapid onset of pain and swelling over the affected salivary gland
tenderness to palpation, with warmth and induration of the overlying skin
suppurative discharge from the duct orifice
multiple glands-bilateral involvement of up to 25% of cases