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This page has moved. Click here to view. ShinglesShingles results from reactivation of the varicella-zoster virus. Shingles is a sporadic disease with an estimated lifetime incidence of 10 to 20 percent shingle. The incidence of shingles increases sharply with advancing age, roughly doubling in each decade past the age of 50 years. Shingles is uncommon in persons less than Pathophysiology Varicella-zoster virus is a highly contagious virus. Varicella represents the primary infection in the nonimmune person. During the primary infection, the virus gains entry into the sensory dorsal root ganglia, where the virus remains latent for decades. Reactivation of the virus occurs following a decrease in Although shingles is not as contagious as the primary varicella infection, persons with reactivated infection can transmit varicella-zoster virus to nonimmune contacts. About 20 percent of patients with shingles develop postherpetic neuralgia. The most established risk factor is Clinical evaluation Shingles typically presents with a prodrome consisting of hyperesthesia, paresthesias, burning dysesthesias or pruritus along the affected dermatome(s). The prodrome generally lasts one to two days but may precede the appearance of skin lesions by up to The skin lesions begin as a maculopapular rash that follows a dermatomal distribution in a "belt-like pattern." The maculopapular rash evolves into vesicles with an erythematous base. The vesicles are painful, and their development is often associated with the occurrence of flu-like symptoms. Although any vertebral dermatome may be involved, T5 and T6 are most commonly affected. The most frequently involved cranial nerve dermatome is the ophthalmic division of the trigeminal nerve. The vesicles crust over within seven to Postherpetic neuralgia is defined as pain that persists for longer than one to three months after resolution of the rash. Affected patients usually report constant burning, lancinating pain. Symptoms tend to abate over time. Less than one quarter of patients still experience pain at six months after the shingles eruption, and fewer than one in 20 has pain at one year. Treatment of shingles Antiviral agents have been shown to decrease the duration of shingles rash and the severity of pain associated with the rash. Benefits have been demonstrated in patients who received antiviral agents within 72 hours after the onset of Acyclovir ( Zovirax) therapy appears to produce a moderate reduction in the development of postherpetic neuralgia. Other antiviral agents, specifically valacyclovir (Valtrex) and famciclovir (Famvir), appear to be at least as effective as Valacyclovir ( Valtrex), a prodrug of acyclovir, is administered three times daily. Compared with acyclovir, valacyclovir may be slightly better at decreasing the severity of pain associated with shingles, as well as the duration of Famciclovir ( Famvir). The advantages of famciclovir are its dosing schedule (three times daily), its longer intracellular half-life compared with acyclovir and its better bioavailability compared with All three antiviral agents are generally well tolerated. The most common adverse effects are nausea, headache, vomiting, dizziness and |