Gums That Peel

Correct answer: C. Perilesional incisional biopsy with a portion submitted for direct immunofluorescence

• A. Incorrect. Excision of the entire involved gingiva is unnecessarily destructive and pointless in a condition that is diffuse and immune-mediated rather than localized.
• B. Incorrect. The center of an ulcer contains only necrotic debris and granulation tissue. The epithelium that carries the diagnostic information has already been lost.
• C. Correct. The immunoreactants are deposited in intact epithelium, so the specimen must include clinically normal-appearing tissue adjacent to the lesion. Submit one portion in formalin for routine histology and a second in Michel’s medium for direct immunofluorescence, which in pemphigus vulgaris shows an intercellular fishnet pattern of IgG and C3.
• D. Incorrect. Cytology samples surface cells only. Tzanck cells may be seen, but it cannot demonstrate the level of epithelial separation or the immunofluorescence pattern, so it is not diagnostic.

Note: The positive Nikolsky sign described here — epithelial sloughing on lateral pressure over clinically normal mucosa — is a hallmark of the vesiculobullous diseases and is a strong clue on any board question.

Correct answer: D. Systemic corticosteroids

• A. Incorrect. Tetracycline rinses have adjunctive anti-inflammatory value in some mucosal conditions but are wholly inadequate as monotherapy for a potentially life-threatening autoimmune disease.
• B. Incorrect. Antivirals treat herpetic infections. There is no viral component to pemphigus vulgaris.
• C. Incorrect. Candidiasis is frequently a secondary complication of corticosteroid therapy and does require treatment when it appears, but it is not the underlying disease.
• D. Correct. Pemphigus vulgaris is an autoantibody-mediated disease against desmoglein 3, and systemic corticosteroids remain first-line. Steroid-sparing agents such as azathioprine or mycophenolate are added for long-term control, and rituximab is now used in refractory disease.

Correct answer: C. Air-powder abrasive polishing

• A. Incorrect. Gentle hand instrumentation is appropriate and necessary. Plaque control substantially reduces gingival inflammation and lessens the severity of desquamative gingivitis.
• B. Incorrect. A soft brush, or an ultra-soft brush, is precisely what should be recommended. Meticulous gentle hygiene is a cornerstone of managing desquamative gingivitis.
• C. Correct. The high-velocity abrasive stream will strip fragile epithelium from the already compromised mucosa and induce extensive painful sloughing. It is contraindicated in any active vesiculobullous condition.
• D. Incorrect. Chlorhexidine is beneficial here. It controls plaque when mechanical hygiene is too painful to perform effectively, though an alcohol-free formulation is better tolerated on ulcerated tissue.

Correct answer: B. Sodium fluoride

• A. Incorrect. Sodium bicarbonate is a mild abrasive with modest buffering capacity. It is not an established anticaries agent.
• B. Correct. Fluoride is the anticaries agent in dentifrice. It reduces enamel solubility by forming fluorapatite, promotes remineralization of early lesions, and inhibits bacterial enolase. In a xerostomic patient, a high-concentration 5000 ppm prescription fluoride paste is the appropriate escalation.
• C. Incorrect. Sodium lauryl sulfate is a detergent and foaming agent. It has no anticaries effect and may aggravate aphthous ulceration and mucosal irritation in susceptible patients.
• D. Incorrect. Hydrated silica is the abrasive component that removes extrinsic stain and biofilm mechanically. It contributes nothing chemically to caries prevention.

Note: Distinguish the agents: stannous fluoride provides both anticaries and antimicrobial action; sodium fluoride is the standard dentifrice anticaries agent; silver diamine fluoride is a professionally applied agent for arresting active caries, not a dentifrice ingredient.