Shingles is a reactivation of the varicella-zoster virus (VZV), the virus that also causes chickenpox. It presents with serious pain on one side of the body with a herpetic rash that follows the path of the affected nerve. Sometimes, though rarely, shingles presents without a rash in a condition known as zoster sine hepete (ZSH).
According to "Infections of the Central Nervous System," edited by W. Michael Scheld et al., the number of cases of shingles that occur without rash is unknown. This is because of the difficulty of diagnosing the condition without the characteristic rash. According to the University of Maryland Medical Center, ZSH usually occurs in older patients.
Persons who experience ZSH still present with the characteristic unilateral pain associated with shingles. They also experience prodrome, the initial symptoms of a herpetic outbreak that occur before a rash; this includes a burning or tingling sensation in the area that will be affected. The University of Maryland Medical Center reports that other symptoms of ZSH include numbness, headache, fever and nausea.
ZSH is difficult to diagnose, but the pain experienced by sufferers can be recognised by diagnosticians. According to Scheld et al., diagnosis can be confirmed through the presence of VZV-specific antibodies as well as VZV DNA in polymerase chain reaction (PCR) testing.
The University of Maryland Medical Center reports that some cases of Bell's palsy may actually be due to ZSH.
According to a study by Y. Furuta et al., of the Department of Otolaryngology at Hokkaido University School of Medicine, people with ZSH who received antiviral drugs along with a course of corticosteroids, which is the primary treatment for shingles, also recovered from outbreak. The study notes that this treatment is only effective for people who have been confirmed through PCR testing to be experiencing a recurrence of VZV.
Complications of ZSH are similar to those of general shingles and include postherpetic neuralgia, a condition in which the pain of shingles does not pass at the same time as the rash clears up. Other potential complications include dissemination of the disease to other parts of the body; this occurs especially in immunocompromised persons. The elderly and immunocompromised more frequently experience complications as a result of VZV recurrence.