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Periodontics · patient case with 2 questions

ANUG — blunted papillae and fetid odour

Scenario: A clinical photograph of ANUG showing BLUNTED PAPILLAE and FETID ODOUR.

Question 1

All of the following bacteria are seen in this condition EXCEPT:

  1. Porphyromonas gingivalis
  2. Prevotella intermedia
  3. Streptococcus viridans
  4. Tannerella forsythia
Show answer and explanation

Correct answer: C. Streptococcus viridans

  • A. Porphyromonas gingivalis is a gram-negative anaerobe and a red complex pathogen found in necrotizing and chronic periodontal disease.
  • B. Prevotella intermedia is a hallmark organism in ANUG and is characteristically elevated, along with spirochetes and fusiform bacteria.
  • C. Correct — this is the EXCEPTION. Streptococcus viridans is a facultative GRAM-POSITIVE aerobe and a normal commensal of the oral cavity. It is the organism of concern for INFECTIVE ENDOCARDITIS after bacteraemia, not a component of the necrotizing periodontal disease flora.
  • D. Tannerella forsythia is another red complex gram-negative anaerobe recovered in periodontal disease.

Note: The classic ANUG flora is the FUSOSPIROCHETAL complex — fusiform bacteria (Fusobacterium) plus SPIROCHETES (Treponema) — with Prevotella intermedia. The clinical triad is PAIN, punched-out/CRATERED interdental papillae, and BLEEDING, with fetid halitosis and a grey pseudomembrane.

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Question 2

What is the treatment?

  1. Tetracycline
  2. Clindamycin
  3. Metronidazole
  4. Amoxicillin
Show answer and explanation

Correct answer: C. Metronidazole

  • A. Tetracycline has broad activity and is used in some periodontal contexts, but it is not the anaerobe-specific agent of choice for ANUG.
  • B. Clindamycin does cover anaerobes and is an alternative, but metronidazole is the standard first-line choice for ANUG.
  • C. Correct. METRONIDAZOLE is the antibiotic of choice because it is specifically active against obligate ANAEROBES — precisely the fusospirochetal flora driving necrotizing periodontal disease. It is used alongside gentle debridement, hydrogen peroxide or chlorhexidine rinses, analgesia, and correction of predisposing factors.
  • D. Amoxicillin alone has inadequate anaerobic coverage; amoxicillin COMBINED with metronidazole is used in aggressive periodontal disease.

Note: Do not overlook the non-pharmacologic side: ANUG is driven by STRESS, SMOKING, immunosuppression, malnutrition and poor oral hygiene. Persistent or unusually severe necrotizing disease should prompt consideration of HIV testing. Warn patients on metronidazole to avoid ALCOHOL (disulfiram-like reaction).

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