Shingles: The Varicella-Zoster Connection…

Shingles, also known as Zoster, is caused by the reactivation of the varicella-zoster virus.  It is a herpes virus.  Following a primary infection with chickenpox (varicella) the virus settles in nerve ganglia and waits to express and raise trouble.  The risk of shingles increases with age and often is related to ganglion compression or injury resulting in a blistering eruption within the distribution of one or two adjacent sensory nerves.  The blistering is unilateral with sharp cut-offs at the anterior and posterior midlines.  I have had many patients with onset after over exertion or having been in a motor vehicle accident.  The virus expresses and follows the distribution of the nerve.  The annual incidence is 1 in 1000 persons and among patients over 75 the rate is more than four times greater.  For caucasian patients the lifetime risk is 10-30%.

The first sign of shingles is usually pain which is often severe and within the distribution of the involved nerve (dermatome).  The patient may feel sick and experience a fever or headache.  Within one to two days of onset of pain a blistering eruption expresses comprised of grouped vesicles on an erythematous base that tracks the distribution of the involved nerve.  The dermatomes most frequently involved are the thoracic (55%), cranial (20% with the trigeminal nerve being most commonly involved), lumbar (15%) and sacral (5%).  Triggering events include pressure on the nerve or nerve ganglion (compression), radiotherapy to the nerve site, spinal surgery, infection, and injury.  To see drawings of dermatomes click HERE.

Pain and general symptoms resolve within 2-3 weeks in children and young adults and 3-4 weeks for older patients.  For elderly patients the earlier the initiation of treatment the better the likelihood of minimizing potential complications.  Involvement of the V1 distribution of the fifth cranial nerve can involve the eye resulting in ophthalmic zoster and uveitis and/or keratitis.  Involvement of blisters extending to the side and tip of the nose (see picture above) is called a positive Hutchinson’s sign.

COMPLICATIONS:

  1. Scarring
  2. Post-herpetic neuralgia (persistent severe pain within the involved sensory nerve distribution)
  3. Ophthalmic zoster–uveitis and/or keratitis
  4. Muscle weakness (5%) with facial nerve palsy (Ramsey Hunt syndrome) being the most common
  5. Disseminated zoster–usually observed in severely ill and immunocompromised patients
  6. Strokes & myocardial infarction?  To read more click HERE
  7. Encephalitis

TREATMENT:

  1. My first line of treatment is Valtrex (valcyclovir) 1 gram, three times a day for one week at onset
  2. Famvir (famcyclovir) 500 mg, three times a day for one week at onset
  3. Acyclovir 800 mg, 5 times a day for one week at onset

Valcyclovir is 80 times stronger than Acyclovir in treating shingles.  Also, systemic steroids (oral, intramuscular or intravenous) may be used in patients over 65 to decrease the potential for developing post-herpetic neuralgia.  This is controversial, but the risk is low and the pain in these patients can be severe and life altering, so it is probably worth the use.

PREVENTION:  The shingles vaccine (RZV) has been improved dramatically and is much more effective in preventing the disease than previous versions that were only 50% effective.  It is recommended for patients 50 years or older.  The newest vaccine is the recombinant zoster vaccine (RZV) and it is effective in reducing herpes zoster and prevention of post-herpetic neuralgia…to read more click HERE.

To read more about shingles, herpes zoster, click HERE and HERE.