Can shingles present without a rash?

Can Shingles Present Without a Rash?

Yes, shingles can definitively present without a rash, a condition known as zoster sine herpete (ZSH), though it is uncommon.

Clinical Recognition of Zoster Sine Herpete

Zoster sine herpete occurs when varicella-zoster virus (VZV) reactivates and causes radicular pain in a dermatomal distribution without the characteristic vesicular rash. 1 This atypical presentation can make diagnosis challenging and requires a high index of suspicion.

Key Clinical Features

• Patients experience dermatomal pain, burning, or discomfort that would typically precede or accompany a zoster rash, but no skin lesions ever develop 1, 2
• The pain follows the same dermatomal distribution as typical shingles, most commonly affecting thoracic, lumbar, or cranial nerve distributions 3
• Constitutional symptoms may be minimal or absent 3
• VZV can produce neurologic and visceral diseases in the absence of both rash and radicular pain 1

Diagnostic Approach

When ZSH is suspected based on dermatomal pain without rash, laboratory confirmation is essential since clinical diagnosis alone is unreliable. 4

• Obtain PCR testing of cerebrospinal fluid if neurologic involvement is suspected 5
• Measure VZV-specific IgG antibody levels, which may be elevated 2
• Consider viral culture or PCR from blood mononuclear cells, as VZV DNA can be detected in blood even without skin lesions 1
• Tzanck smear, immunofluorescent viral antigen studies, or PCR can provide definitive confirmation when atypical presentations occur 4, 3

Additional Atypical Presentations

Beyond complete absence of rash, shingles can present with other atypical features that complicate diagnosis:

• The rash may be faint, evanescent, localized to a small area, or difficult to recognize in individuals with darker skin pigmentation 4
• Nonspecific lesions may appear that lack the typical vesicular appearance initially 4
• Some patients develop painless herpes zoster, presenting with rash but without the characteristic pain 6
• VZV meningitis can occur with or without the rash of chickenpox or shingles 5

Treatment Considerations

Even without visible rash, antiviral therapy should be initiated promptly when ZSH is suspected based on clinical presentation and confirmed by laboratory testing. 2

• Oral acyclovir, valacyclovir, or famciclovir are first-line treatments for uncomplicated cases 7, 8
• Intravenous acyclovir is recommended for severe, disseminated, or invasive disease, particularly in immunocompromised patients 7
• Treatment should be started as soon as possible after diagnosis to reduce viral replication and prevent complications 7
• Continue antiviral therapy until clinical resolution is achieved 7

Critical Pitfall to Avoid

Delays in diagnosis of ZSH have been associated with increased mortality in some cases, making prompt recognition and treatment initiation crucial. 4 The absence of rash should not exclude the diagnosis when dermatomal pain and appropriate risk factors are present. Consider ZSH particularly in:

• Elderly patients with unexplained dermatomal pain 9
• Immunocompromised hosts (HIV infection, transplant recipients, malignancy, chronic steroid use) 3, 8
• Patients with hyperesthesia in a specific nerve root distribution 2

Complications Without Rash

ZSH can lead to serious complications despite the absence of cutaneous manifestations:

• Lateral sinus thrombosis from VZV-associated thrombophlebitis has been reported 2
• Various neurologic complications including motor neuropathies, encephalitis, and Guillain-Barré syndrome can occur 3
• Postherpetic neuralgia may develop even without preceding rash 8