A 25-year-old presents with vesicular rash over the T6 dermatome, severe burning pain, and a history of chickenpox at age 7. The causative virus persists in which structure after primary infection?

• A Epidermal basal cells of the affected skin dermatome
• B Peripheral motor neurons innervating the dermatome
• C Peritoneal macrophages draining the visceral pleura
• D Dorsal root ganglion neurons (sensory ganglia) ✓

Explanation

Varicella-zoster virus (VZV) establishes latency in sensory neurons of the dorsal root ganglia (and also cranial nerve ganglia — trigeminal, geniculate) after primary varicella infection. During reactivation (triggered by immunosuppression, stress, or ageing), the virus travels anterograde along sensory axons to the skin of the corresponding dermatome, causing herpes zoster (shingles). The thoracic dermatomes (T3–L3) are most commonly affected. VZV does NOT establish latency in the skin or motor neurons. Treatment is with acyclovir (or valacyclovir/famciclovir) within 72 hours of rash onset to reduce pain duration; postherpetic neuralgia prevention benefits from the live attenuated zoster vaccine (Zostavax) or recombinant subunit vaccine (Shingrix).

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.