Can herpes zoster present bilaterally (on both sides of the body)?

Can Shingles Occur on Both Sides of the Body?

Yes, shingles can present bilaterally, but this is rare and typically occurs only in severely immunocompromised patients—the classic unilateral dermatomal pattern remains the hallmark of herpes zoster in immunocompetent individuals. 1, 2

Understanding the Typical Presentation

• Herpes zoster classically affects a single unilateral dermatome because the virus reactivates from one dorsal root or cranial nerve ganglion where it has remained latent after primary varicella infection 3
• The strictly unilateral distribution confined to one dermatome is the defining clinical feature that distinguishes shingles from other vesicular eruptions 2
• Prodromal pain, burning, or abnormal sensations precede the rash by 24-72 hours in the affected dermatome 2

When Bilateral Presentation Occurs

Bilateral herpes zoster, termed "herpes zoster duplex bilateralis," is an extremely rare atypical manifestation seen almost exclusively in severely immunocompromised patients. 4

High-Risk Populations for Atypical Bilateral Disease

• Patients with hematologic malignancies (e.g., chronic lymphocytic leukemia, multiple myeloma) on active chemotherapy are at highest risk for bilateral or multidermatomal involvement 4, 1
• HIV-infected patients with low CD4 counts may develop non-contiguous bilateral herpes zoster 4
• Organ transplant recipients on chronic immunosuppression can present with atypical bilateral patterns 1
• Elderly patients with chronic kidney disease have been reported to develop bilateral lumbar multidermatomal herpes zoster 5

Clinical Patterns of Atypical Bilateral Disease

• Multidermatomal herpes zoster involves more than one contiguous unilateral dermatome and is more common than true bilateral disease, typically affecting cervical dermatomes in immunocompromised hosts 5
• Non-contiguous bilateral herpes zoster (herpes zoster duplex) involves separate dermatomes on both sides of the body simultaneously 4
• Disseminated herpes zoster is defined by skin lesions involving more than three dermatomes, evidence of visceral organ involvement, or hemorrhagic lesions—this requires immediate intravenous acyclovir 1

Critical Diagnostic Pitfalls

• Do not dismiss bilateral vesicular eruptions as "not shingles" without considering the patient's immune status—atypical presentations may lack classic dermatomal distribution or prodromal pain in immunocompromised hosts 2, 1
• Obtain laboratory confirmation (viral culture, PCR, or direct fluorescent antibody testing) in any immunocompromised patient with atypical presentation, absence of characteristic pain, or bilateral involvement 2, 1
• Assess for disseminated disease by checking for visceral involvement (hepatitis, pneumonia, encephalitis) when bilateral or multidermatomal lesions are present 1

Management of Bilateral or Atypical Herpes Zoster

Any patient with bilateral herpes zoster should be treated as severely immunocompromised and requires intravenous acyclovir 10 mg/kg every 8 hours, not oral therapy. 1

Treatment Algorithm

• Initiate IV acyclovir immediately for bilateral, multidermatomal (≥3 dermatomes), or disseminated disease 1
• Continue IV therapy for a minimum of 7-10 days and until all lesions have completely scabbed 1
• Consider temporary reduction or discontinuation of immunosuppressive medications if clinically feasible in cases of disseminated or invasive herpes zoster 1
• Monitor renal function at initiation and once or twice weekly during IV acyclovir therapy, with dose adjustments for renal impairment 1
• Suspect acyclovir resistance if lesions fail to begin resolving within 7-10 days and obtain viral culture with susceptibility testing 1
• Switch to foscarnet 40 mg/kg IV every 8 hours for confirmed acyclovir-resistant VZV until clinical resolution 1

Special Monitoring Considerations

• Immunocompromised patients develop new lesions for 7-14 days or longer (compared to 4-6 days in healthy individuals) and heal more slowly 1
• Without adequate antiviral therapy, some immunocompromised patients develop chronic ulcerations with persistent viral replication 1
• The risk of disseminated varicella-zoster infection rises to 10-20% when antiviral therapy is not initiated promptly in immunocompromised individuals 3

Infection Control for Bilateral Disease

• Implement both airborne and contact precautions for any patient with bilateral or disseminated herpes zoster, regardless of immune status 3
• Require negative air-flow rooms and continue precautions until all lesions are dry and crusted 3
• Healthcare workers with bilateral or disseminated zoster must be excluded from duty until all lesions have dried and crusted 3

Key Takeaway

While bilateral shingles is possible, it signals severe immunocompromise and mandates aggressive intravenous antiviral therapy, not the standard oral regimen used for typical unilateral disease. 1, 4 Any clinician encountering bilateral vesicular eruptions should immediately assess immune status, obtain confirmatory testing, and escalate to IV acyclovir while evaluating for disseminated infection. 1, 2