Shingles Can Occur in Multiple Noncontiguous Sites, Though It's Rare
Shingles (herpes zoster) typically presents in a single dermatomal distribution, but it can occur in multiple noncontiguous sites, particularly in immunocompromised individuals. This atypical presentation is rare but well-documented in medical literature.
Typical Presentation of Herpes Zoster
Herpes zoster (shingles) is caused by reactivation of the varicella-zoster virus (VZV) that remains dormant in sensory nerve ganglia after primary chickenpox infection. The classic presentation includes:
- Painful vesicular rash in a unilateral dermatomal distribution
- Typically affecting a single dermatome
- Preceded by prodromal symptoms (pain, burning, tingling) in the affected area
- Progressive development of lesions over 4-6 days 1
According to the Centers for Disease Control and Prevention, shingles typically appears as "a painful vesicular rash typically appearing in a dermatomal distribution of one or two sensory-nerve roots" 2.
Atypical Presentations in Multiple Sites
While uncommon, shingles can present in multiple noncontiguous dermatomes in certain circumstances:
Disseminated Herpes Zoster
- Defined as the presence of more than 20 lesions outside the primary or adjacent dermatomes 3
- More common in immunocompromised patients
- Increases risk for complications including hepatitis, encephalitis, and pneumonitis 3
Zoster Multiplex
- Very rare presentation involving multiple disparate dermatomes
- Cases have been documented with involvement of up to 7 disparate dermatomes 4
- Referred to as "zoster duplex unilateralis" or "zoster duplex bilateralis" when involving 2 noncontiguous dermatomes on one or both sides of the body, respectively 4
Non-dermatomal Distribution
- Can occur without following classic dermatomal patterns
- Described as "non-dermatomal disseminated herpes zoster" 3
- More likely in patients with compromised immune systems
Risk Factors for Multiple-Site Involvement
Patients at higher risk for atypical or multidermatomal presentations include:
- Immunocompromised individuals (HIV, cancer patients, transplant recipients)
- Patients on immunosuppressive medications (chemotherapy, steroids)
- Elderly patients
- Those with underlying malignancies 1, 3
Clinical Implications
Multiple-site herpes zoster has important clinical implications:
- May be more difficult to diagnose due to atypical presentation
- Often requires more aggressive antiviral therapy
- Higher risk of complications including postherpetic neuralgia
- May indicate underlying immunosuppression that warrants investigation
- May require intravenous antiviral therapy rather than oral medication 1
Management Considerations
For patients with multiple-site or disseminated zoster:
- Prompt initiation of antiviral therapy is critical
- Higher doses and longer duration of treatment may be required
- Immunocompromised patients may need intravenous acyclovir initially 1
- Treatment should continue until all lesions have crusted over 1
- Close monitoring for systemic complications is necessary
Diagnostic Challenges
Multiple-site zoster can present diagnostic challenges:
- May be mistaken for other vesicular eruptions or drug reactions
- Laboratory confirmation (direct fluorescent antibody testing, PCR) may be necessary
- Consider zoster in any immunocompromised patient with vesicular lesions, even if distribution is atypical 5, 3
In summary, while shingles classically presents in a single dermatomal distribution, clinicians should be aware that it can occur in multiple noncontiguous sites, particularly in immunocompromised patients. This atypical presentation requires prompt recognition and aggressive treatment to prevent complications.