What is the name of the reactivation of latent varicella zoster leading to a painful rash along a dermatomal distribution?

• A. Shingles
• B. Mononucleosis
• C. Measles
• D. Herpes simplex encephalitis

Answer: (A)

Reactivation of latent varicella-zoster virus in sensory ganglia leads to shingles, a painful, vesicular rash that follows a single dermatomal distribution. After the initial chickenpox infection, the virus hides out in dorsal root or trigeminal ganglia and can reactivate when cell-mediated immunity wanes with age or illness. When it reactivates, the virus travels along the affected nerve to the skin, producing a unilateral, painful eruption that typically stays within one dermatome and may be preceded by burning or tingling. The pain can persist after the rash heals, a complication known as postherpetic neuralgia. Other options aren’t correct because mononucleosis is due to EBV and presents with fever and sore throat rather than a dermatomal rash; measles is a systemic illness with a generalized rash; herpes simplex encephalitis affects the brain, not producing a localized dermatomal skin eruption.