Makindo Medical Notes

Definition: Parotitis is inflammation of the parotid salivary gland. The parotid drains via Stensen’s duct, which opens opposite the upper second molar 😬. Clinically, parotitis often reflects reduced salivary flow (stasis) ➝ ascending infection/inflammation from oral flora.

Aetiology🧠

Saliva normally “flushes” bacteria out of the duct 🚿. When flow drops (dehydration, fasting, anticholinergics, post-op state) 🥤🚫 or the duct is blocked (stone/stricture/tumour) 🪨, bacteria can ascend the duct and inflame the gland. This explains pain and swelling worse with meals 🍽️ (salivary stimulation against obstruction/inflammation) and pus from the duct 🟡 in suppurative bacterial cases.

Causes (high-yield categories) ✅

• Viral 🦠: mumps (classic), influenza/parainfluenza, EBV/CMV, HIV (often bilateral, systemic symptoms; no frank pus).
• Acute bacterial suppurative 🧫🚨: usually Staphylococcus aureus; also streptococci + anaerobes. Often unilateral; risks: dehydration, frailty, poor oral intake, post-op state.
• Obstructive 🪨: sialolithiasis, duct stricture, external compression (recurrent episodes; worse with meals).
• Autoimmune/inflammatory 🧬: Sjögren’s (dry eyes/mouth 👁️👄), IgG4-related disease (firm enlargement), sarcoid.
• Other 🎯: neoplasms (usually painless mass), meds causing xerostomia (anticholinergics 💊), malnutrition.

Clinical features 👀

• Local: pre-auricular/angle-of-mandible swelling 😖, tenderness, warmth 🔥, erythema.
• Duct signs: inspect and milk Stensen’s duct—purulent discharge 🟡 strongly suggests bacterial suppurative parotitis.
• Meal-related pain: suggests obstruction or ductal inflammation 🍋🍽️.
• Systemic: fever 🤒, malaise; viral cases may be bilateral.
• Red flags 🚩: sepsis, rapidly progressive swelling, facial nerve weakness 😵‍💫, fluctuance/abscess, airway compromise, immunosuppression.

Differentials (don’t miss) 🧩

• Dental infection 🦷: focal tooth tenderness; different anatomical epicentre.
• Otitis externa/mastoiditis 👂: ear-focused symptoms/signs.
• Cervical lymphadenitis 🧠➡️🫛: discrete nodes rather than gland.
• Parotid tumour 🎯: painless persistent mass; possible facial nerve involvement.
• Submandibular sialadenitis 👇: swelling under jaw; Wharton’s duct.

Assessment (GP/ED) 🩺

• History: onset, unilateral/bilateral, fever 🤒, meal-related pain 🍽️, dehydration 🥤, meds (anticholinergics/opioids 💊), sicca symptoms 👁️👄, immunosuppression.
• Examination: vitals; gland tenderness/erythema; oral cavity; duct orifice + discharge; hydration status; cranial nerves (esp. VII).
• Investigations (targeted) 🔬:
  • Mild/uncomplicated: often clinical.
  • FBC/CRP if systemic illness.
  • Culture if pus expressed 🧫 (guides tailoring).
  • Ultrasound if recurrent, suspected stone 🪨, abscess, or unclear diagnosis.
  • CT if deep neck infection, abscess, severe disease, airway concerns.
  • Mumps testing if compatible illness (public health implications).

Management (core steps for everyone) 🧴🍋

Supportive measures: rehydrate 💧, analgesia (paracetamol/ibuprofen if appropriate), warm compresses ♨️, gentle gland massage (posterior ➝ anterior) 🤲, meticulous oral hygiene 🪥, and sialogogues (e.g., lemon drops) 🍋 to boost flow. These work because restoring salivary “flushing” reduces stasis (the upstream driver) and helps clear debris/infection.

Antibiotics (expanded) 💊🚑

First-line (common UK regimen) ✅

• Mild–moderate, oral route: Flucloxacillin PO + Metronidazole PO (covers staph + anaerobes).
• Severe / sepsis / can’t take PO: Flucloxacillin IV + Metronidazole (IV in some guidelines).

Penicillin allergy options ⚠️

• Clindamycin (PO for mild–moderate; IV for severe) — single agent that covers many staph + anaerobes.
• Doxycycline + metronidazole is used in some NHS guidance (especially where MRSA risk/pen allergy is a concern).

MRSA risk / known colonisation 🧷

• Vancomycin + metronidazole is recommended in some NHS board guidance (then tailor to sensitivities).
• Other guidance suggests clindamycin if sensitive, or linezolid if MRSA is resistant to clindamycin (specialist/micro input sensible).

Alternative single-agent approach 🔁

• Co-amoxiclav (PO or IV depending on severity) is listed as a second-line option in some UK antimicrobial pathways.

Important prescribing notes 🧠

• If you choose co-amoxiclav, don’t add metronidazole “for extra anaerobe cover” (it’s usually redundant) ❌.
• Send a pus swab from Stensen’s duct if you can express discharge, and step down IV→PO once improving 🎯.
• No improvement within 24–48h or fluctuance? Think stone/abscess 🪨💥 → ultrasound/CT and ENT/maxfax.

When to refer urgently / admit 🚨

• Sepsis/systemic toxicity 🤒🩸
• Immunocompromised or frail with dehydration 🧓💧
• Suspected abscess, deep neck space infection, or failure to improve in 24–48h 🧨
• Airway compromise, severe trismus, dysphagia 😮‍💨
• Facial nerve weakness or persistent painless mass (malignancy concern) ⚠️

Complications ⚠️

• Abscess formation 🧨
• Deep neck spread (rare but high-stakes) 🧠➡️🦴
• Chronic sialadenitis with recurrent swelling 🔁
• Mumps complications: orchitis, meningitis/encephalitis 🦠

Memory hooks 🧠✨

• Pus at Stensen’s duct = bacterial until proven otherwise 🟡➡️💊
• Worse with meals = obstruction/ductal problem 🍽️🪨
• Bilateral + viral prodrome = think mumps/viral 🦠🤒