Gingival enlargement is characteristically seen in all of the following EXCEPT one. Which is the EXCEPTION?

Correct answer: D. Primary herpetic gingivostomatitis

• A. This IS a cause. Phenytoin is the classic drug-influenced gingival enlargement, alongside cyclosporine and the calcium channel blockers (nifedipine, amlodipine). It begins interdentally and is fibrotic.
• B. This IS a cause. Scurvy produces swollen, spongy, haemorrhagic gingiva from defective collagen synthesis, since vitamin C is required for the hydroxylation of proline and lysine.
• C. This IS a cause. Sarcoidosis, along with leukaemia, Wegener granulomatosis and Crohn disease, produces gingival enlargement through granulomatous or leukaemic infiltration.
• D. CORRECT — this is the EXCEPTION. PRIMARY HERPETIC GINGIVOSTOMATITIS produces a fiery-red, painful, ULCERATIVE gingivitis with vesicles that rupture into shallow ulcers, together with fever and lymphadenopathy. The gingiva is intensely inflamed and swollen from oedema, but the disease is not characterised by true gingival ENLARGEMENT — an increase in tissue bulk from cellular and matrix proliferation.

Note: Classify gingival enlargement by cause: INFLAMMATORY (plaque, mouth breathing); DRUG-INFLUENCED (phenytoin, cyclosporine, CCBs); SYSTEMIC/CONDITIONAL (pregnancy, puberty, vitamin C deficiency, leukaemia, sarcoidosis, Crohn, Wegener); NEOPLASTIC; and HEREDITARY gingival fibromatosis.