Definition
A.Herpes zoster is a viral infection manifested by painful, vesicular lesions on the skin, limited to one side of the body, following one body dermatome.
Incidence
A.Infection may occur at any age; however, it is more common in older adults and the elderly. It occurs in 10% to 20% of the U.S. population.
Pathogenesis
A.After the primary episode of chickenpox (varicella zoster), the virus remains dormant in the body. Herpes zoster occurs when the varicella virus has been stimulated and reactivated in the dorsal root ganglia, producing the clinical manifestations of herpes zoster. Infection usually lasts 7 to 10 days but may be longer in elderly or debilitated patients.
Predisposing Factors
A.Adulthood.
B.Immunocompromised patients.
C.Spinal cord trauma or injury.
Common Complaints
A.Prodrome: Itching, burning, tingling, or painful sensation at lesion sites.
B.Active: Malaise, fever, headache, pruritic rash on the skin.
Other Signs and Symptoms
A.Lesions: Clusters of vesicles on an erythemic base that burst and produce crusted lesions; commonly seen on the chest and back area. Distribution of lesions typically appears along a single dermatome.
B.Motor weakness (may be seen in approximately 5% of patients).
Subjective Data
A.Determine onset, location, and progression of rash.
B.Ask the patient about prodromal symptoms: Burning, itching, tingling, or painful sensation at site prior to lesions breaking out.
C.Evaluate patient status regarding immunosuppressive agents, diseases, and so forth.
Physical Examination
A.Check temperature, pulse, respirations, and blood pressure.
B.Inspect:
1.Observe skin for lesions, noting characteristics and distribution.
2.Inspect eyes, ears, nose, and throat.
C.Auscultate: Auscultate heart and lungs.
Diagnostic Tests
A.Usually none.
B.Culture vesicular lesions.
C.Consider Tzanck smear.
D.Young patients with herpes zoster: Consider and test for HIV.
Differential Diagnoses
A.Herpes zoster.
B.Varicella.
C.Poison ivy.
D.Herpes simplex virus (HSV).
E.Contact dermatitis.
F.Coxsackievirus.
G.Postherpetic neuralgia.
Plan
A.General interventions: Comfort measures. Instruct the patient to apply wet dressings (Burow’s solution) on site for 30 to 60 minutes at least four times a day. Calamine lotions may be used as needed; oatmeal (Aveeno) bath for comfort; acetaminophen (Tylenol) as needed for malaise, temperature, and comfort.
B. 
See Section III: Patient Teaching Guide Herpes Zoster (Shingles).
1.Tell the patient the rash usually lasts approximately 2 to 3 weeks.
2.Instruct the patient to monitor for signs/symptoms of postherpetic neuralgia.
3.Instruct the patient to call if symptoms worsen or do not improve, or if signs of bacterial infection occur.
4.Emphasize to the patient that the virus is easily transmitted to vulnerable persons.
C.Pharmaceutical therapy:
1.Antiviral medications should be initiated within 24 to 48 hours after outbreak:
a.Acyclovir (Zovirax) 800 mg five times daily for 7 days.
b.Famciclovir (Famvir) 500 mg by mouth three times daily for 7 days.
c.Valacyclovir (Valtrex) 1,000 mg by mouth three times daily for 7 days.
2.Acetaminophen (Tylenol) or ibuprofen as needed for pain or discomfort.
3.Narcotics may be used for severe pain as needed.
4.Postherpetic neuralgia:
a.Postherpetic neuralgia may be treated with narcotics or other pain-relieving medications.
b.Long-term medications may be needed for control of pain:
i.Gabapentin 100 to 600 mg three times daily.
ii.Amitriptyline 25 mg every bedtime or other low-dose tricyclic antidepressants.
5.If secondary bacterial infection of the skin occurs, apply silver sulfadiazine (Silvadene) topically to site until resolved.
6.Use of steroids is controversial. Corticosteroids may be used with caution. May increase risk of dissemination.
Follow-Up
A.As needed for complications.
B.Monitor the patient for complications: Postherpetic neuralgia, Guillain–Barré syndrome, motor weakness, secondary infection, meningoencephalitis, ophthalmic and facial palsy, corneal ulceration, and so forth.
Consultation/Referral
A.Consult with physician if secondary infection occurs or if secondary complications arise.
B.Consult ophthalmologist immediately for any eye involvement
Individual Considerations
A.Pregnancy: Acyclovir is in the category C drug classification. The safety and efficacy of the use of the antiviral medications during pregnancy need to be considered.
B.Geriatrics:
1.Postherpetic neuralgia occurs in approximately 15% of patients. It is commonly seen in the elderlypatient.
2.The Centers for Disease Control and Prevention (CDC) recommends the shingles vaccine for those 50 years and older. There are two types available; the CDC recommends the recombinant vaccine (Shingrix) over the live vaccine unless contraindicated:
a.Shingrix—recombinant zoster vaccine guidelines:
i.Administration dosing:
•Two doses administered intramuscularly (IM): first dose given on day 1, and, the second dose should be administered 2-6 months after the first.
ii.Indications:
•Immunocompetent patients older than 50 years.
•Patients who previously received the varicella vaccine and the (live) zoster vaccine. The CDC recommends waiting 5 years to administer the Shingrix vaccine if Zostavax was previously administered.
•Patients with comorbid conditions.
iii.Contraindications:
•Patients with known allergy to components of the vaccine.
b.Zostavax—zoster live vaccine guidelines:
i.Administration dosing:
•One-time subcutaneous injection.
ii.Indications: Older than 60 years.
iii.Contraindications:
•Patients with anaphylactic reactions to gelatin or neomycin.
•Immunocompromised patients:
–Planned immunosuppression
–Patients receiving low-dose immunosuppressive therapy.
–Household contacts of immunocompromised hosts.
•Pregnancy, although this drug is not indicated for women of childbearing age.
C.Geriatric red flags:
1.Avoid first-generation anti-holinergics due to risk of confusion, dry mouth, constipation, and other anti-cholinergic effects or toxicity.
2.Avoid use of nonsteroidal anti-inflammatory drugs (NSAIDs) in patients that have chronic kidney disease Stage IV or less (creatinine clearance <30 mL/min).