Tzanck smear showing multinucleated giant cells is most consistent with infection by which virus?

• A. Herpes simplex virus
• B. Molluscum contagiosum virus
• C. Bacterial impetigo
• D. Candida albicans

Answer: (A)

Multinucleated giant cells on a Tzanck smear reflect cytopathic effects produced by herpesviruses, where infected keratinocytes fuse to form large multinucleated cells. This pattern is classically seen with herpes simplex virus infections (and also with varicella-zoster virus), making HSV the best fit among the options. Molluscum contagiosum would show molluscum bodies in infected cells, not multinucleated giant cells. Bacterial impetigo has no viral cytopathic changes, and Candida albicans presents with budding yeast and pseudohyphae rather than giant cells. So the finding most aligns with herpes simplex virus infection.