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Pathology · patient case with 5 questions

Vesiculobullous Disease

demo: 55-year-old female

chief: “Spicy food burns terribly and my gums peel.”

history: Six-month history of oral ulceration preceding any skin involvement. No fever.

meds: None

findings: Diffuse buccal mucosal erythema with ragged erosions, desquamative gingivitis, and flaccid bullae that rupture readily. Gentle lateral pressure on adjacent normal-appearing mucosa produces a new blister.

Question 1

The buccal erythema and sensitivity to spicy foods in this patient indicate:

  1. Mucosal involvement by the disease process
  2. Simple mechanical trauma from the toothbrush
  3. A superimposed candidal infection
  4. An allergic contact reaction to toothpaste
Show answer and explanation

Correct answer: A. Mucosal involvement by the disease process

  • A. Correct. Pemphigus vulgaris characteristically presents in the mouth first, and the eroded mucosa is exquisitely sensitive to acidic and spicy foods.
  • B. Mechanical trauma would not produce widespread bullae or a positive Nikolsky sign.
  • C. Candidiasis presents with removable white plaques or diffuse atrophic erythema, not flaccid bullae and ragged erosions.
  • D. Contact reactions localize to the areas of contact and resolve on withdrawal of the agent.

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Question 2

Which diagnostic test confirms the diagnosis?

  1. Culture and sensitivity of the lesion
  2. Serum complete blood count with differential
  3. Biopsy of perilesional tissue submitted for direct immunofluorescence
  4. Exfoliative cytology of the ulcer base
Show answer and explanation

Correct answer: C. Biopsy of perilesional tissue submitted for direct immunofluorescence

  • A. Culture addresses infection; this is an autoimmune disease.
  • B. A CBC does not diagnose an autoimmune blistering disease.
  • C. Correct. Perilesional tissue submitted in Michel's medium for direct immunofluorescence shows intercellular IgG and C3 in a fishnet pattern around keratinocytes — the diagnostic finding in pemphigus vulgaris.
  • D. Cytology may show Tzanck cells but is not diagnostic and cannot distinguish pemphigus from viral acantholysis.

Note: Sampling perilesional — not ulcerated — tissue is critical; an ulcer base has already lost the epithelium that carries the diagnostic immune deposits.

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Question 3

The blistering produced by gentle lateral pressure on clinically normal mucosa is termed:

  1. Wickham striae
  2. A positive Nikolsky sign
  3. Koplik spots
  4. A positive Tzanck test
Show answer and explanation

Correct answer: B. A positive Nikolsky sign

  • A. Wickham striae are the fine white lacy lines of lichen planus.
  • B. Correct. Nikolsky sign reflects intraepithelial acantholysis — desmosomal adhesion has failed, so the epithelium slides apart under shear.
  • C. Koplik spots are the blue-white buccal macules of measles.
  • D. The Tzanck test is a cytologic smear looking for acantholytic cells, not a clinical sign.

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Question 4

Which condition is most important to distinguish from this presentation in a patient with widespread oral ulceration?

  1. Fissured tongue
  2. Amalgam tattoo
  3. Geographic tongue
  4. Primary herpetic gingivostomatitis
Show answer and explanation

Correct answer: D. Primary herpetic gingivostomatitis

  • A. Fissured tongue is a developmental grooving of the dorsum, unrelated to blistering disease.
  • B. An amalgam tattoo is a stable pigmented macule with no inflammatory component.
  • C. Geographic tongue is an asymptomatic or mildly sensitive migratory pattern on the dorsal tongue with no ulceration.
  • D. Correct. Primary herpetic gingivostomatitis also produces widespread oral ulceration and painful gingivae, but it is acute, febrile, occurs mostly in children, is preceded by vesicles on keratinized tissue, and is self-limiting over 10–14 days.

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Question 5

A child with primary herpetic gingivostomatitis and fever should NOT be given which analgesic?

  1. Aspirin, because of the risk of Reye syndrome
  2. Ibuprofen
  3. Topical viscous lidocaine used sparingly
  4. Acetaminophen
Show answer and explanation

Correct answer: A. Aspirin, because of the risk of Reye syndrome

  • A. Correct. Aspirin given to a child with a viral illness carries a risk of Reye syndrome — acute encephalopathy with hepatic steatosis.
  • B. Ibuprofen is acceptable in a well-hydrated child and carries no Reye risk.
  • C. Topical anesthetic is used cautiously and sparingly, with attention to total dose, but it is not contraindicated.
  • D. Acetaminophen is the standard antipyretic and analgesic for these children.

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