Start practicing

Pathology · patient case with 4 questions

Man with bleeding gums, easy bruising and poor wound healing

Patient: Male, 45 years old

Chief complaint: “My gums bleed a lot.”

Background: Vitamin C deficiency. Depression.

Current findings: Easy bruising, poor wound healing, bone pain. Periodontal disease.

Question 1

With this cofactor deficiency, which enzyme will NOT function properly, leading to poor collagen formation?

  1. Hydrogen peroxidase
  2. Peptidase
  3. Lysyl oxidase
  4. Lysyl hydroxylase
Show answer and explanation

Correct answer: D. Lysyl hydroxylase

  • A. Hydrogen peroxidase is not the vitamin C–dependent enzyme of collagen synthesis.
  • B. Peptidases cleave peptide bonds and are not vitamin C–dependent.
  • C. Lysyl OXIDASE cross-links collagen and elastin but requires COPPER, not vitamin C. This is the intended trap: near-identical name, different cofactor.
  • D. CORRECT. Ascorbate is the essential cofactor for PROLYL and LYSYL HYDROXYLASE. Without hydroxylation of proline and lysine residues, the procollagen triple helix cannot form stable cross-links. The result is fragile capillaries, defective connective tissue, haemorrhagic gingiva and impaired wound healing — scurvy.

Note: Watch the pair: lysyl HYDROXYLASE needs vitamin C; lysyl OXIDASE needs copper.

Permanent page for this question

Question 2

Which oral manifestation is most characteristic of this deficiency?

  1. Thrombocytopenia
  2. Angular cheilitis
  3. Spontaneously bleeding, swollen gingiva
  4. Leukopenia
Show answer and explanation

Correct answer: C. Spontaneously bleeding, swollen gingiva

  • A. Platelet count is NORMAL in scurvy. The bleeding is vascular in origin, not a platelet defect — a favourite distractor.
  • B. Angular cheilitis points to RIBOFLAVIN (B2) or iron deficiency, or to candidal infection.
  • C. CORRECT. The hallmark of scurvy in the mouth is swollen, spongy, haemorrhagic gingiva that bleeds with minimal or no provocation, caused by capillary fragility and breakdown of periodontal connective tissue.
  • D. White cell count is unaffected.

Permanent page for this question

Question 3

All of the following contribute to a HIGH caries risk EXCEPT one. Which is the EXCEPTION?

  1. Low fluoride exposure
  2. The number of yearly dental visits
  3. A high number of existing restorations
  4. A reduced salivary flow rate
Show answer and explanation

Correct answer: B. The number of yearly dental visits

  • A. Low fluoride exposure raises risk by leaving enamel more soluble and reducing remineralisation.
  • B. CORRECT — this is the EXCEPTION. How often a patient attends is a UTILISATION measure, not a biological risk factor. Attendance alone neither raises nor lowers caries risk; what matters is saliva, past caries experience, fluoride and diet.
  • C. A heavily restored dentition is direct evidence of past and recurrent caries activity, and past caries is the strongest single predictor of future caries.
  • D. Reduced salivary flow removes buffering, clearance and remineralisation capacity — a major risk factor.

Permanent page for this question

Question 4

A different patient presents with erythematous gingiva and an atrophic, depapillated tongue. Which vitamin deficiency does this combination most suggest?

  1. Vitamin D
  2. Vitamin C
  3. Vitamin K
  4. Vitamin E
Show answer and explanation

Correct answer: B. Vitamin C

  • A. Vitamin D deficiency affects mineralisation — rickets and osteomalacia — not gingival bleeding.
  • B. CORRECT. The combination of erythematous, bleeding gingiva with papillary atrophy points to vitamin C deficiency.
  • C. Vitamin K deficiency impairs clotting factors II, VII, IX and X, producing bleeding, but not papillary atrophy of the tongue.
  • D. Vitamin E deficiency is rare and causes neurological and haemolytic problems.

Note: B-vitamin deficiencies also cause glossitis. B2 gives angular cheilitis and a magenta tongue; B12 and folate give a beefy red tongue with anaemia.

Permanent page for this question

Practice patient cases Pathology study notes