Shingles – Diagnosis, Symptoms and Treatment

What is Shingles?

Shingles is a medical condition characterized by the reactivation of the varicella-zoster virus.  Varicella-zoster is the virus responsible for chickenpox – this disease frequently affects toddlers and presents diffuse bodily rash with blisters.  After contracting this disease, the virus regresses and remains dormant in nerve cells called the dorsal root ganglia.

These bundles or ganglia of cells house varicella-zoster until a time when the body becomes stressed, or the immune system is suppressed.  This causes the virus to wake up or reactivate and travel down nerve dermatomes, producing painful blisters and rash.  This usually occurs on one side of the body.

If it involves the face, it may lead to permanent visual loss.  Other shingles complications include post-herpetic neuralgia – a painful syndrome that develops in a subset of patients that experience shingles.

Due to this condition's importance, patients must understand its causes, symptoms, and treatment.

What Causes Shingles?

Shingles is caused by reactivation of the varicella-zoster virus – the same virus responsible for chickenpox during youth.  After the primary infection, the virus regresses into the dorsal root ganglion that surrounds the spinal cord.  Certain conditions provoke viral reactivation:

•         Fever
•         Sun exposure
•         Stress
•         Infection
•         Immune suppression – HIV/AIDS, chemotherapy, corticosteroid use
•         Advanced age
•         Pregnancy

Once the virus reactivates, it typically travels down one or more dermatomes – nerve tracts on either side of the body.  This typically involves the chest or abdomen.  It can also affect the ophthalmic division of the trigeminal nerve – resulting in visual loss.  These cases require urgent ophthalmology consultation and intravenous antiviral medications.

How Common is Shingles?

Shingles is a prevalent condition that is frequently evaluated in the primary care clinic.  This disease may require referral to a dermatology specialist.

The incidence of Shingles is about 4 cases per 1,000 Americans each year.  In people aged 60 and older, the incidence is approximately 10 cases per 1,000 Americans each year.

Signs and Symptoms

The most common symptom of include:

•         Burning pain
•         Blister-like rash
•         Redness & warmth
•         Malaise

Sometimes the pain will precede the development of rash.  The rash follows one or more dermatomes down one side of the body – often the chest, abdomen, or face.  Involvement of the eye can result in a visual loss (zoster ophthalmicus).

Diagnosis

Shingles is typically diagnosed based on symptoms and physical examination findings.  The diagnosis is suggested in older patients presenting with the development of a unilateral painful rash in a dermatomal distribution with a blister-like appearance.

Your doctor will occasionally confirm the diagnosis by sending a swab of the rash for varicella-zoster PCR and herpes simplex virus PCR.  They may even send a sample for the culture of these two viruses.  Herpes simplex virus should always be considered as it can cause a rash that has a similar appearance to shingles.

Shingles Treatment

Shingles should ideally be prevented before an outbreak.  The Zostavax shingles vaccine is indicated in patients with or without a known history of chickenpox or shingles.  Zostavax immunization is indicated in patients as early as age 50 - most patients are recommended to receive immunization at age 60.

If a patient develops a shingles outbreak, they should generally seek medical attention as soon as possible because initiating treatment after 72 hours of symptoms is unlikely to have any benefit.

The most commonly prescribed drugs for shingles include the following antivirals:

•       Zovirax (Acyclovir)
•       Valtrex (Valacyclovir)

Patients should be instructed to avoid contact with newborns, pregnant women, patients without a history of chickenpox or shingles, and patients with immunosuppression (e.g., HIV/AIDS, cancer patients).  The virus can be spread via respiratory droplets – but it is most frequently transmitted by direct contact with the blisters of the rash.  Once the blisters have all crusted over, the virus is no longer contagious.

Patients with nerve pain – neuropathic pain – may require Tylenol treatment (acetaminophen) or NSAIDs (Advil, Naprosyn).  In severe cases, their pain may need to be controlled with opiate analgesics such as:

•         Codeine
•         Tramadol
•         Vicodin (hydrocodone-acetaminophen)
•         Percocet (oxycodone-acetaminophen)

Opiates should be used at the lowest dose possible and for the shortest duration of time possible.  They should also be used cautiously in the elderly due to the increased risk of falls.

Some patients with Shingles develop long-standing nerve pain.  These patients may respond to medications used to treat peripheral neuropathy, such as:

•         Neurontin (gabapentin)
•         Lyrica (pregabalin)
•         Cymbalta (duloxetine)

References:

1.     Fashner J, Bell AL. Herpes zoster and post-herpetic neuralgia: prevention and management. Am Fam Physician. 2011 Jun 15;83(12):1432-7. - https://www.aafp.org/afp/2011/0615/p1432.html
2.     Neuzil KM, Griffin MR. Preventing Shingles and Its Complications in Older Persons. N Engl J Med. 2016 Sep 15;375(11):1079-80. - https://www.ncbi.nlm.nih.gov/pubmed/15930418