Disseminated Zoster: Shingles in Multiple Dermatomes

Herpes zoster (shingles) typically reactivates in a single dermatome. Disseminated zoster involves ≥2 non-contiguous dermatomes or systemic spread; it occurs in <2% of cases and signals immune compromise.

Clinical Features

• Vesicular rash in multiple dermatomes (often >3)
• May cross midline
• Systemic symptoms: fever, malaise, hepatosplenomegaly
• Visceral involvement: pneumonitis, hepatitis, encephalitis, meningoencephalitis

Risk Factors

• Immunosuppression: HIV/AIDS (CD4 <200), hematologic malignancy, transplant, corticosteroids (>20 mg prednisone/day × 2 weeks), biologics, chemotherapy.
• Age >60 (immunosenescence).
• Autoimmune disease on immunosuppressants.

Diagnosis

• Clinical: characteristic rash in multiple dermatomes.
• PCR for VZV DNA (skin lesion, blood, CSF).
• Direct fluorescent antibody (DFA) or culture (less sensitive).

Management

• IV acyclovir 10 mg/kg q8h × 7–10 days (standard for disseminated disease).
• Transition to oral valacyclovir 1g TID when improving.
• Supportive care: hydration, pain control, monitor for visceral complications.
• Ophthalmology consult if ophthalmic division (V1) involved.
• Address underlying immunosuppression if possible.

Prevention

• RZV (Shingrix) 2-dose series: ≥50 years, or ≥19 years if immunocompromised. >90% efficacy.
• Not for active zoster; vaccinate after resolution.

Disseminated zoster is a medical emergency requiring IV antivirals and immunocompromise evaluation.