Sialadenitis is bacterial infection of a salivary gland, usually due to an obstructing stone or gland hyposecretion. Symptoms are swelling, pain, redness, and tenderness. Diagnosis is clinical. CT, ultrasonography, and MRI may help identify the cause. Treatment is with antibiotics.
Etiology of Sialadenitis
Sialadenitis usually occurs after hyposecretion or duct obstruction but may develop without an obvious cause. The major salivary glands are the parotid, submandibular, and sublingual glands.
Sialadenitis is most common in the parotid gland and typically occurs in
Patients in their 50s and 60s
Chronically ill patients with xerostomia
Patients with Sjögren syndrome
Adolescents and young adults with anorexia
Children (age 1 to18 years) with juvenile recurrent parotitis of undetermined etiology
The most common causative organism is Staphylococcus aureus; others include streptococci, coliforms, and various anaerobic bacteria.
Inflammation of the parotid gland can also develop in patients who have had radiation therapy to the oral cavity or radioactive iodine therapy for thyroid cancer (1, 2, 3). Although sometimes described as sialoadenitis, this inflammation is rarely a bacterial infection, particularly in the absence of fever. Juvenile recurrent parotitis is a disorder of unknown etiology affecting children (most commonly 4 to 6 years old) and often resolving by puberty. Allergy, infection, genetic inheritance, and autoimmune disorders have not been confirmed as causes. Except for possibly mumps, juvenile recurrent parotitis remains the second most common form of parotitis in children (4).
Etiology references
1. Erkul E, Gillespie MB: Sialendoscopy for non-stone disorders: the current evidence. Laryngoscope Investig Otolaryngol 1 (5):140–145, 2016. doi: 10.1002/lio2.33
2. An YS, Yoon JK, Lee SJ, et al: Symptomatic late-onset sialadenitis after radioiodine therapy in thyroid cancer. Ann Nucl Med 27 (4):386–391, 2013. doi: 10.1007/s12149-013-0697-5
3. Kim YM, Choi JS, Hong SB, et al: Salivary gland function after sialendoscopy for treatment of chronic radioiodine-induced sialadenitis. Head Neck 38 (1):51–58, 2016. doi: 10.1002/hed.23844
4. Schwarz Y, Bezdjian A, Daniel SJ: Sialendoscopy in treating pediatric salivary gland disorders: a systematic review. Eur Arch Otorhinolaryngol 275 (2):347–356, 2018. doi: 10.1007/s00405-017-4830-2
Symptoms and Signs of Sialadenitis
Fever, chills, and unilateral pain and swelling develop in patients with sialadenitis. The salivary gland is firm and diffusely tender, with erythema and edema of the overlying skin. Pus can often be expressed from the duct by compressing the affected gland and should be cultured. Focal enlargement may indicate an abscess.
Diagnosis of Sialadenitis
CT, ultrasonography, or MRI
CT, ultrasonography, and MRI can confirm sialadenitis or abscess that is not obvious clinically, although MRI may miss an obstructing stone. If pus can be expressed from the duct of the affected gland, it is sent for Gram stain and culture.
Treatment of Sialadenitis
Antistaphylococcal antibiotics
Local measures (eg, sialagogues, warm compresses)
Initial treatment for sialadenitis is with antibiotics active against S. aureusS. aureus
Hydration, sialagogues (eg, lemon juice, hard candy, or some other substance that triggers saliva flow), warm compresses, gland massage, and good oral hygiene are also important. Abscesses require drainage.
Occasionally, a superficial parotidectomy, parotid duct ligation, or submandibular gland excision is indicated for patients with chronic or relapsing sialadenitis.
Other Salivary Gland Infections
Mumps often causes parotid swelling (see table Causes of Parotid and Other Salivary Gland Enlargement).
Patients with HIV infection often have parotid enlargement secondary to one or more lymphoepithelial cysts.
Cat-scratch disease caused by Bartonella infection often invades periparotid lymph nodes and may infect the parotid glands by contiguous spread. Although cat-scratch disease is self-limited, antibiotic therapy is often provided, and incision and drainage are necessary if an abscess develops.
Atypical mycobacterial infections in the tonsils or teeth may spread contiguously to the major salivary glands. The purified protein derivative (PPD) test may be negative, and the diagnosis may require biopsy and tissue culture for acid-fast bacteria. Treatment recommendations are controversial. Options include surgical debridement with curettage, complete excision of the infected tissue, and use of anti-tuberculosis drug therapy (rarely necessary).
Salivary glands may also be involved in sarcoidosis and IgG4-related disease. Sjogren syndrome may manifest as parotid or submandibular gland swelling
