Conditions:
Shingles (Herpes Zoster)
Related Terms
•
Post-Herpetic Neuralgia
Principal Proposed Treatments
•
Capsaicin, Proteolytic Enzymes
Other Proposed Treatments
•
Adenosine Monophosphate (AMP), Vitamin B12, Vitamin E
Herpes zoster (shingles) is an acute, painful infection caused by the varicella-zoster virus, the organism that causes chicken pox. It develops many years after the original chicken pox infection, typically in the elderly or those with compromised immune systems. The first sign may be a tingling feeling, itchiness, or shooting pain on an area of skin. A rash may then appear, with raised dots or blisters forming. When the rash is at its peak, rash symptoms can range from mild itching to extreme pain. People with shingles on the upper half of the face should seek medical attention, as the virus may cause damage to the eyes.
Shingles usually resolves without complications within 3 to 5 weeks. However, in some people, especially the elderly, the pain persists for months or years. This condition, known as post-herpetic neuralgia (PHN), is thought to be due to continuing irritation of the nerves after the infection is over.
Conventional medical treatment for shingles includes antiviral drugs (acyclovir, famicyclovir, valacyclovir). When used properly, these lead to faster resolution of symptoms including lesions and acute neuralgia, and may reduce the incidence and severity of PHN. Steroids (prednisone) and tricyclic antidepressants (amitriptyline) are also prescribed to lessen shingles symptoms, and the former might help prevent PHN.
Individuals who do develop PHN may be treated with steroids, antidepressants, and topical creams (see Capsaicin, below). In severe cases, nerve blocks might be used.
Principal Proposed Treatments for Shingles (Herpes Zoster)
For the initial attack of shingles, proteolytic enzymes may be helpful.Capsaicin cream is an FDA-approved treatment for PHN.
Proteolytic Enzymes
There is some evidence that proteolytic enzymes may be helpful for the initial attack of shingles.
Proteolytic enzymes are produced by the pancreas to aid in digestion of protein, and certain foods also contain these enzymes. Besides their use in digestion, these enzymes may have some effects in the body as a whole when taken orally. The most-studied proteolytic enzymes include papain (from papaya), bromelain (from pineapple), and trypsin and chymotrypsin (extracted from the pancreas of various animals).
A double-blind study of 190 people with shingles compared proteolytic enzymes to the standard antiviral drug acyclovir.1 Participants were treated for 14 days and their pain was assessed at intervals. Although both groups had similar pain relief, the enzyme-treated group experienced fewer side effects.
Similar results were seen in another double-blind study in which 90 individuals were given either an injection of acyclovir or enzymes, followed by a course of oral medication for 7 days.2
Proteolytic enzymes are thought to benefit cases of shingles by decreasing the body's inflammatory response and regulating immune response to the virus.
For more information, including dosage and safety issues, see the full proteolytic enzymes article.
Capsaicin: Useful for Post-Herpetic Neuralgia
Capsaicin, the "hot" in hot peppers, has been found effective for treating the pain related to PHN, and has been approved by the FDA for that purpose. Capsaicin is thought to work by inhibiting chemicals in nerve cells that transmit pain (see also cayenne).
Dosage
Topical capsaicin cream is available in 2 strengths, 0.025 and 0.075%. Both preparations are indicated for use in neuralgia. The cream should be applied sparingly to the affected area 3 to 4 times daily. Treatment should continue for several weeks as the benefit may be delayed. Capsaicin creams are approved over-the-counter drugs and should be used as directed.
Safety Issues
Over-the-counter creams containing concentrated capsaicin are recognized as safe, but caution should be used near the eyes and mucous membranes. Mild to moderate burning may occur at first, but it decreases over time.
Other Proposed Treatments for Shingles (Herpes Zoster)
Adenosine Monophosphate (AMP)
Adenosine monophosphate (AMP), a natural by-product of cell metabolism, has been studied as a possible treatment for initial shingles symptoms as well as PHN prevention.
In a double-blind placebo-controlled study of 32 people with shingles, AMP was injected 3 times a week for 4 weeks.4 At the end of the 4-week treatment period, 88% of those treated with AMP were pain-free versus only 43% in the placebo group; all participants still in pain were then given AMP, and no recurrence of pain was reported in 3 to 18 months of follow-up. However, this was a highly preliminary study, and more evidence is needed before AMP can be considered a proven treatment for shingles.
Oral AMP has not been tried for this condition. Note: Do not self-inject AMP products meant for oral consumption.
Vitamins
Vitamin E and B12 have also been suggested as possible treatments for PHN, but the evidence that they work is extremely weak.5,6,7
View References
Last reviewed March 2002 by Medical Review Board
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