[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Conditions](https://durgical.com/en/conditions/) › Acute suppurative sialadenitis (bacterial parotitis)

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# Acute suppurative sialadenitis (bacterial parotitis)

A bacterial infection of a salivary gland, usually the parotid, causing a painful swollen cheek. It is typical of dehydrated elderly or post-operative patients.

Updated 2026-11-01

## Structures involved

Tap one to see what it is and open it in 3D.

- [Parotid gland](https://durgical.com/en/anatomy/parotid-gland/)
- [Submandibular gland](https://durgical.com/en/anatomy/submandibular-gland/)
- [Sublingual gland](https://durgical.com/en/anatomy/sublingual-gland/)
- [Facial nerve (VII)](https://durgical.com/en/anatomy/facial-nerve/)
- [Facial nerve branches](https://durgical.com/en/anatomy/temporal-branches-of-facial-nerve/)
- [Masseter](https://durgical.com/en/anatomy/superficial-part-of-masseter/)
- [Mandible](https://durgical.com/en/anatomy/mandible/)
- [Neck lymph nodes](https://durgical.com/en/anatomy/lymph-nodes-of-neck/)
- [Tongue](https://durgical.com/en/anatomy/tongue/)
- [External carotid artery](https://durgical.com/en/anatomy/external-carotid-artery/)

## Why it happens

- [Patterns of acute inflammation: serous, fibrinous, purulent, abscess, ulcer](https://durgical.com/en/general-pathology/patterns-of-acute-inflammation-serous-fibrinous-purulent-abscess-ulcer/)
- [Salivary secretion](https://durgical.com/en/physiology/salivary-secretion/)
- [Salivary glands: serous and mucous acini](https://durgical.com/en/histology/salivary-glands-serous-and-mucous-acini/)

## What it is

Acute bacterial infection of a major salivary gland, most often the parotid and less often the [submandibular gland](https://durgical.com/en/anatomy/submandibular-gland/). It follows reduced saliva flow, which lets oral bacteria ascend the duct into the gland, and presents with sudden painful swelling and pus at the duct opening.

## Who gets it

Uncommon but classic in hospitalised and post-operative patients, elderly people who are dehydrated or taking drying medications, and people with poor oral hygiene or chronic illness. It also occurs in premature newborns. Viral mumps is a separate disease and became less frequent with MMR vaccination.

## Causes

- Staphylococcus aureus is the most frequent organism, including methicillin-resistant strains
- Streptococci, Haemophilus influenzae and oral anaerobes
- Gram-negative bacteria in hospitalised or debilitated patients
- Duct obstruction by stones or stricture, especially in the submandibular gland

## Risk factors

- Dehydration, particularly after surgery or in the elderly
- Medications that reduce saliva: anticholinergics, antihistamines, diuretics, tricyclic antidepressants
- Poor oral hygiene and dental disease
- Nil by mouth or tube feeding (no chewing stimulus)
- Salivary stones, Sjögren disease, previous [head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) radiotherapy
- Diabetes, immunosuppression, malnutrition

## Pathophysiology

Saliva normally flushes the duct and contains antibacterial substances. When flow falls, saliva stagnates and bacteria from the mouth ascend the parotid (Stensen) duct, which opens opposite the upper second molar, or the submandibular (Wharton) duct. The parotid is especially vulnerable because its watery serous saliva has less protective mucin. Inflammation inside the tight parotid capsule causes intense pain, and untreated infection can form an abscess and spread to deep neck spaces.

## Classification

- Acute suppurative (bacterial) sialadenitis
- Chronic or recurrent sialadenitis (often obstructive)
- Viral sialadenitis (mumps and others), discussed separately
- Neonatal suppurative parotitis

## Symptoms and signs

- Sudden, painful, firm swelling over the angle of the jaw (parotid) or under the jaw (submandibular), usually on one side
- Pain that worsens when eating
- Redness, warmth and tenderness of the overlying [skin](https://durgical.com/en/anatomy/skin/)
- Pus coming from the duct opening, especially when the gland is massaged
- Fever, malaise and foul taste in the mouth
- Difficulty opening the mouth (trismus)

## Red flags

- Difficulty breathing or swallowing, or swelling of the floor of the mouth (deep neck spread)
- High fever, hypotension or confusion (sepsis)
- A fluctuant mass that does not improve with antibiotics (abscess)
- Facial weakness (may indicate tumour or severe complication)

## Diagnosis

**Clinical**
Mainly clinical: unilateral tender gland swelling with pus expressed from Stensen or Wharton duct on gentle massage, in a patient with risk factors such as dehydration.

**Tests**
Gram stain and culture of the ductal pus to guide antibiotics; blood count and inflammatory markers; blood cultures if septic; [kidney](https://durgical.com/en/anatomy/kidney/) function and electrolytes to assess hydration.

**Imaging**
Ultrasound first to look for an abscess or stone. Contrast CT if an abscess, deep neck spread or failure to improve is suspected.

## Differential diagnosis

- Mumps (viral parotitis): often bilateral, no pus from the duct
- Obstructive sialolithiasis
- Salivary gland tumour
- Sjögren disease or HIV-associated parotid enlargement
- Dental abscess or masseteric space infection
- Cervical lymphadenitis

## Goal of treatment

Clear the infection, restore salivary flow and hydration, drain any abscess and prevent spread or recurrence.

## Treatment

**Conservative**
Rehydration (intravenous fluids when needed), sialogogues such as sour sugar-free candies, warm compresses, gentle gland massage toward the duct and good oral hygiene.

**Medical**
Empirical antibiotics active against Staphylococcus aureus and oral flora (e.g. an anti-staphylococcal penicillin or a beta-lactam with a beta-lactamase inhibitor, adding anti-MRSA cover when risk exists), adjusted to culture; analgesia.

**Surgical**
Incision and drainage of an abscess that does not resolve, protecting branches of the [facial nerve](https://durgical.com/en/anatomy/facial-nerve/).

**Procedure**
Sialendoscopy or stone removal for duct obstruction, usually after the acute infection settles.

**Follow-up**
Nursing: fluid balance, temperature, oral care, airway and swallowing, and review of drying medications.

## Complications

- Abscess of the gland
- Spread to the parapharyngeal and other deep neck spaces with airway compromise
- Sepsis
- Salivary fistula to the skin
- Chronic or recurrent sialadenitis
- Facial nerve palsy (rare)

## Prognosis

Good with early hydration and antibiotics; most cases resolve within days to a week. Outcomes are worse in frail, septic or immunosuppressed patients, and recurrence is common if the predisposing cause persists.

## Prevention

- Adequate hydration of post-operative, elderly and critically ill patients
- Regular oral care in hospitalised and bedridden patients
- Reviewing medications that dry the mouth
- Treating dental disease and salivary stones

## Test yourself

Think of the answer, then tap the question to see it.

## Which organism most often causes acute suppurative parotitis?

Staphylococcus aureus, including methicillin-resistant strains.

## What is the classic patient profile?

An elderly, dehydrated or post-operative patient, often on drying medications and with poor oral hygiene.

## Where does the parotid duct open, and what is seen there in bacterial parotitis?

Opposite the upper second molar on the buccal mucosa; pus can be expressed from it by massaging the gland.

## How does bacterial parotitis differ from mumps?

Bacterial parotitis is usually unilateral with pus from the duct and leucocytosis; mumps is viral, often bilateral and has no purulent discharge.

## What are two key nursing measures?

Restoring hydration and providing regular oral hygiene, plus monitoring temperature and airway.

[Add to my cards (5)](https://durgical.app/estudiar/?add=/en/conditions/acute-suppurative-sialadenitis/)

## Related conditions

- [Mumps](https://durgical.com/en/conditions/mumps/)
- [Sialolithiasis (salivary stones)](https://durgical.com/en/conditions/sialolithiasis/)
- [Parotid gland tumours](https://durgical.com/en/conditions/parotid-gland-tumours/)
- [Sjögren disease](https://durgical.com/en/conditions/sjogren-disease/)
- [Dehydration (fluid volume deficit)](https://durgical.com/en/conditions/dehydration/)
- [Deep neck infection and Ludwig angina](https://durgical.com/en/conditions/deep-neck-infection-and-ludwig-angina/)
- [Dental caries](https://durgical.com/en/conditions/dental-caries/)
- [Sepsis and septic shock](https://durgical.com/en/conditions/sepsis-and-septic-shock/)
- [HIV infection and AIDS](https://durgical.com/en/conditions/hiv-infection-and-aids/)

Educational information, not medical advice. For any symptom, see a health professional.

Sources: [Salivary gland infections](https://medlineplus.gov/ency/article/001041.htm) (MedlinePlus, US National Library of Medicine, 2026).

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Source: https://durgical.com/en/conditions/acute-suppurative-sialadenitis/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/conditions/acute-suppurative-sialadenitis/