Herpes Zoster

Welcome to PT 635 Pathophysiology of Complex Patient Problems This is a wiki created by and for the students in the School of Physical Therapy at Bellarmine University in Louisville KY. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!

Original Editors - Heather Lindsey and Kaycee Stone from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - Kaycee Stone, Heather Dixon, Lucinda hampton, Donald John Auson, Kim Jackson, Elaine Lonnemann, Wendy Walker, Evan Thomas, WikiSysop, Chelsea Mclene and Nupur Smit Shah  

Definition/Description

Herpes Zoster, commonly called Shingles, is characterized by a painful rash with blisters. It results from reactivation of the dormant varicella-zoster virus, also known as chickenpox, that reactivates within sensory ganglia. The severity increases with advancing age.

Prevalence

Shingles will affect 1 in 3 people in the United States, with approximately 1 million cases each year. Half of the people affected are over the age of 60, but people of any age can develop herpes zoster if they have previously contracted the varicella-zoster virus.

Characteristics/Clinical Presentation

At first, there is only pain, tingling, or burning before a rash appears. This is generally on one side of the body. The rash appears as red areas, then blisters that break and form crusts. This rash usually lasts two to three weeks and often affects an area from the spine to the chest or abdomen, as well as the ears, face, or eyes. The rash can be widespread, like chickenpox, in cases involving an immunocompromised patient. Other assosciated symptoms include flu-like symptoms such as fever, chills, malaise, headache, joint pain, and swollen glands. If the eye is affected, the virus can cause blindness.

Postherpetic neuralgia, which is pain lasting longer than 90 days following the initial herpes zoster rash, was found in 24% of patients in a quality of life study by Drolet et al. Acute pain and postherpetic neuralgia were most commonly associated with anxiety, depression, difficulty sleeping, and decreased ability to participate in activities of daily living.

Associated Co-morbidities

Immunocompromised people, like people undergoing treatment for cancer, leukemia, lymphoma, HIV, and patients on immunosuppressive drugs are at an increased risk of developing shingles. Older adults are also at an increased risk for developing it.

Medications

Acyclovir, valacyclovir, and famciclovir are antiviral medications that are commonly prescribed to treat shingles to shorten the duration and ease the severity of the outbreak. Analgesics may also be prescribed to help with the pain related to shingles. Other medications that are used to treat shingles include steroids and anticonvulsants.

Diagnostic Tests/Lab Tests/Lab Values

The diagnosis is generally made based upon an examination of the skin and taking medical history. A skin sample may be taken to determine if the skin is infected by the varicella-zoster virus. Health care providers may run blood tests, which will not diagnose Herpes Zoster, but will show elevated white blood cells and antibodies to the virus that causes chicken pox.

Etiology/Causes

Herpes Zoster is caused by the dormant varicella zoster, also known as chickenpox, becoming active again, often years following the initial incidence of the infection. The dormant virus becomes active when the patient's immune system declines due to immunosuppression or aging.

Systemic Involvement

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Medical Management (current best evidence)

Shingles can be treated conservatively using nonsteroidal anti-inflammatory drugs or wet dressings with 5% aluminum acetate. These dressings should be applied for 30-60 minutes and be done 4-6 times each day. Lotions such as calamine can also be used to help relieve symptoms. 

The Varicella-zoster virus vaccine is used as a preventative measure for shingles.  A literature update by Dworkin et al. for the Mayo Clinic recommends pharmacological management via implementation of the vaccine as a preventative intervention. The vaccine decreases the risk of developing herpes zoster by half, and thus, reduces the risk of neuropathic pain. In terms of treating postherpetic neuralgia (PHN), the authors suggest topical lidocaine administered via a 5% patch or as a gel to be a tolerable and first-line treatment for localized PHN. The authors did not find antidepressants to be an effective treatment for PHN in the literature or in their clinical experience. Clinical trial research suggests that high dose capsaicin topical patches may produce a reduction in symptoms for a few months, but long-term effects weren't known at the time of the literature review. Conflicting evidence exists for the benefits of botulinum toxin injections for neuropathic pain resulting from herpes zoster. 

Physical Therapy Management (current best evidence)

If the facial nerve is affected by herpes zoster and peripheral facial palsy results, facial exercises have been found to be effective. These exercises include exercises to stimulate functional movement in the face, achieve summetry, to improve motor control, reduce synkinesis, improve perception of movement, and promote emotional expression. Mirror therapy, mime therapy, facial muscular re-education, and Kabat's exercises were found to be effective means of facial rehabilitation techniques. 

Alternative/Holistic Management (current best evidence)

Acupuncture has recently been studied for its efficacy in the treatment of pain associated with herpes zoster. One 2011 study by Ursini et al. found that acupuncture may be as effective as standard pharmacological treatments for pain control. This is advantageous because it may reduce the medication load of the patient.

Differential Diagnosis

Herpes simplex virus may mimic herpes zoster if it is recurrent and occurring in a dermatomal pattern. Laboratory tests are needed to avoid the misdiagnosis Lymphangioma circumscriptum can also mimic the rash associated with shingles.

Case Reports/ Case Studies

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Resources

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Recent Related Research (from Pubmed)

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