Herpes Zoster (Shingles)
The reactivation of the varicella zoster virus (VZV) may occur at any time after the primary VZV infection. Herpes zoster (HZ) often begins as a prodrome of intense pain associated with pruritis, tingling, tenderness or hyperesthesia in more than 90% of patients. This pain can be misdiagnosed as pleurisy, surgical abdomen or myocardial infarction if severe enough. Rarely, the pain is not followed by the cutaneous eruption of herpes zoster and the condition is known as zoster sine herpete (zoster without rash). In most cases, a painful eruption of grouped vesicles on an erythematous base develops within a sensory dermatome, usually on the trunk. In some cases, the face, neck, scalp, or extremity may be involved. The cutaneous eruption typically involves a single dermatome and rarely crosses the midline.
Zoster usually resolves without sequelae in children and young adults with intact immune systems. The pain, cutaneous eruptions and complications of zoster become more severe with increasing age and immune compromise.
Complications of zoster include: post-herpetic neuralgia (PHN), secondary bacterial infection, scaring, ophthalmic zoster, Ransay-Hunt syndrome, meningoencephalitis, motor paralysis, pneumonitis, and hepatitis. The severity and incidence of post-herpetic neuralgia increase with age, with 10-15% of all zoster patients developing the complication. Ophthalmic zoster is a severe complication that occurs in 7% of cases with 20-70% developing associated ocular disease including blindness. Herpes zoster in immunocompromised persons maybe very severe. Zoster in HIV-infected patients may assume a number of unusual manifestations, especially that of persistent crusted, verrucous lesions. Disseminated cutaneous disease, defined as more than 20 vesicles outside the area of primary or adjacent dermatomes, and or visceral involvement occurs in approximately 10% of immunocompromised persons.