Acute Necrotizing Ulcerative Gingivitis

Definition

• Acute necrotising ulcerative gingivitis (ANUG) = rapid-onset, severely painful gingival infection.
• Key signs:
  • “Punched-out” interdental papillae
  • Grey necrotic pseudomembrane
  • Spontaneous bleeding
  • Fetid halitosis (± metallic taste)
• Concept: opportunistic dysbiosis → anaerobic shift (classically Fusobacterium + spirochaetes).
• Triggered when host defences dip:
  • stress, smoking, poor oral hygiene
  • malnutrition/dehydration
  • systemic illness or immunosuppression

Pathophysiology (why it looks/acts this way)

• Reduced gingival perfusion + impaired neutrophil function (e.g. smoking, dehydration, stress hormones, systemic disease).
• Creates a hypoxic gingival sulcus → anaerobes proliferate.
• Anaerobic toxins/proteases → superficial epithelial necrosis of papillae
  • → cratered, “punched-out” papillae
• Necrotic surface + inflammation → fibrin + slough
  • → grey pseudomembrane
• Exposed nerve endings → disproportionate pain/tenderness.
• Inflamed microvasculature → easy/spontaneous bleeding.
• If untreated:
  • may extend into periodontium → necrotising periodontitis
  • rarely spreads into adjacent tissues → deep space infection / Ludwig’s angina (airway risk)

Who is at risk? 👀

• Local factors: poor oral hygiene, gingivitis/periodontitis, recent dental plaque build-up.
• Physiological stressors: acute stress, sleep deprivation, dehydration, intercurrent viral illness.
• Exposures: smoking (biggest modifiable factor), alcohol excess, poor diet/malnutrition.
• Systemic vulnerability: immunosuppression (HIV, chemo, steroids), poorly controlled diabetes, haematological disease.

Key clinical features 🧭

• Severe gingival pain with brushing/eating; patients often avoid oral care → worsens cycle.
• Punched-out interdental papillae with grey pseudomembrane and spontaneous bleeding.
• Fetor oris + metallic taste; hypersalivation may occur.
• Regional lymphadenopathy; low-grade fever/malaise can occur, but marked systemic illness should prompt escalation.

Red flags 🚩 (urgent dental/maxfax input)

• Airway/space infection features: trismus, dysphagia/odynophagia, drooling, floor-of-mouth swelling, “hot potato” voice, stridor.
• Spreading infection: facial/neck swelling, fluctuance, rapidly worsening pain or asymmetry.
• Systemic toxicity: rigors, high fever, tachycardia, hypotension, confusion.
• Extension beyond gingivae: necrotising stomatitis/periodontitis or visible tissue sloughing into mucosa.

Assessment 🩺

• Clinical diagnosis: document distribution, papillary crater formation, bleeding, pseudomembrane, halitosis, and any signs of spread.
• Risk screen: smoking, nutrition, hydration, stress/sleep, recent illness; check diabetes control and immunosuppressants.
• If unwell: record observations, assess hydration; consider blood glucose/ketones if diabetic and febrile.
• Consider HIV testing where appropriate (consented) if severe/recurrent ANUG or other risk indicators.

Management 💊🪥

Principles: treat pain, reduce anaerobe burden, and mechanically remove necrotic plaque. Antibiotics are an adjunct (most useful when there’s systemic involvement, spreading cellulitis, immunosuppression, or failure of local measures), but debridement + oral hygiene drive recovery.

1. Immediate measures (start now):
   • Analgesia: paracetamol ± NSAID if suitable; encourage fluids/soft diet.
   • Antiseptic rinse: chlorhexidine gluconate 0.12–0.2% 10–15 mL for 30 s BD for 7–14 days (spit out). Warm saline rinses after meals.
   • Gentle oral care: soft toothbrush; reassure that mild bleeding is expected and improves as inflammation settles.
2. Dental management (key step):
   • Urgent dental review (ideally within 24–48 h) for gentle debridement once pain controlled, then definitive periodontal care.
   • Remove plaque/necrotic debris → restores oxygenation and breaks the anaerobic niche.
3. Antibiotics (when indicated; use local guidance):
   • Your requested regimen: co-amoxiclav 625 mg PO TDS plus metronidazole 400 mg PO TDS for 7 days.
   • Practical notes: avoid alcohol with metronidazole (during + 48–72 h after); check interactions (e.g. warfarin). In penicillin allergy, discuss an alternative regimen (often metronidazole-based ± macrolide) with dental/maxfax/ID in line with local policy.
4. Address drivers (prevents recurrence):
   • Smoking cessation support; improve hydration and nutrition; tackle stress/sleep.
   • Optimise diabetes control; review immunosuppression only with the relevant specialist team.

Follow-up & safety-netting 📞

• Dental review within 24–48 h to complete debridement and plan periodontal prevention.
• Seek urgent help if fever, spreading swelling, dysphagia, trismus, voice change, or deterioration despite treatment.
• Reinforce technique once pain settles: brush twice daily, interdental cleaning, regular dentist/hygienist care.

Differentials 🔍

• Primary herpetic gingivostomatitis (diffuse gingival inflammation + vesicles/ulcers, systemic upset, often children/young adults).
• Aphthous ulceration (discrete ulcers, no papillary “cratering”, less halitosis).
• Candidiasis (white plaques that wipe off; burning more than severe focal papillary pain).
• Haematological disease (e.g. leukaemia): disproportionate bleeding, pallor, bruising, systemic features.
• Desquamative gingivitis (lichen planus/pemphigoid) or vasculitic oral lesions if chronic/recurrent/atypical.

Complications (if untreated) ⚠️

• Progression to necrotising periodontitis → attachment loss, tooth mobility, recession.
• Rare spread to deep spaces → deep neck infection/Ludwig’s angina and sepsis (airway risk).

Prescribing notes 📝

• Metronidazole: avoid alcohol during treatment and for 48–72 h after last dose; check warfarin interaction.
• Pregnancy/breastfeeding: short courses of metronidazole are generally compatible; co-amoxiclav commonly used-check BNF/local guidance.
• Hepatic impairment: metronidazole may need caution; review dosing as per BNF and clinical context.

Patient advice 💬

• Brush gently twice daily with a soft brush; bleeding should reduce as healing starts.
• Use chlorhexidine/saline rinses after meals; keep hydrated; avoid smoking and alcohol (especially with metronidazole).
• Complete antibiotics if prescribed; stop and seek advice if rash, facial swelling, severe diarrhoea, or worsening symptoms.

Local dental/Trust protocols vary; the antibiotic regimen above reflects the requested combination (co-amoxiclav + metronidazole for 7 days) alongside standard urgent local care.