Herpes Zoster

Herpes Zoster

Also known as Shingles

An acute viral infection  of the nerve cells and surrounding skin.

Characterized by a rash of blisters, can be very painful but is not life-threatening.

Caused by the varicella zoster virus that also causes chickenpox.

• Shingles usually appears, band of blisters on one side of the chest or back, but it can occur anywhere on the body, including on the face and near the eyes.

Varicella-zoster virus

Varicella-zoster virus (VZV) infection causes two clinically distinct forms of disease:

Varicella (chickenpox)

Herpes zoster (shingles)

Herpes virus (DNA)

Primary infection results in varicella (chickenpox)

Recurrent infection results in herpes zoster (shingles)

Shingles Epidemiology

Transmission• Direct contact with open sores of shingles rash• Can pass to someone who has never had the chickenpox

High incidence groups• Anyone who had chickenpox• People over the age of 50

Incubation period• 10–21 days

Pathophysiology

Herpes zoster

Infection of nerves and dermatome

Reactivation in dorsal root ganglia

Enter into nerve endings and transport to dorsal root ganglia (DRG) where it lies DORMANT in sensory nerve ganglia, dorsal root.

Secondary viremia

Further viral replication in liver and spleen

Primary viremia in bloodstream

Viral replication in regional lymph nodes

VZV enters through the respiratory tract

Causes & Risk factors

Age

common in people older

than 50.

Diseases

that weaken the immune system, such as HIV/AIDS and cancer.

Cancer treatments

Undergoing radiation or

chemotherapy can lower the resistance to diseases and may trigger

shingles.

Immunosuppressant Drugs

prolonged use of steroids,

such as prednisone.

Clinical Symptoms

Initial prodromal stage

The first signs of shingles may include Headache

Feeling generally unwell

Myalgia

Fever 

Acute stage A rash will begin to develop, often

causing a pain.

Itching or tingling sensation in the area of the affected nerve.

A fluid filled painful rash then develops a few days after and commonly occurs either on one side of the face or body.

Fluid-filled blisters that break open and crust overin 7-10 days and this clears within 2-4 weeks.

Complications1. Post herpetic neuralgia

(PHN)

Post herpetic neuralgia can cause severe nerve pain that persists after the rash. PHN occurs most often in elderly people and in people whose immune systems have been compromised.

2. Ophthalmic shingles

Shingles in or around an eye can cause painful eye infections that may result in vision loss.

Ramsay Hunt syndromeOtherwise known as herpes zoster oticus, is inflammation of several of the nerves that come out of the brain. The symptoms of Ramsay Hunt syndrome are facial paralysis, ear pain.

Encephalitis

Hearing problems

Bacterial infections on the skin.

Cranial Nerve Involvement

I ophthalmic

II maxillary

III mandibular

Zoster Ophthalmicus

Shingles Diagnosis

Skin sample

Infected with

varicella-zoster virus

Blood test

Increase in white blood cells

Management of acute herpes zoster

Antiviral medication to reduce pain and complications. Should be started within 24 hours of first symptom  .These medications include:

Acyclovir (Zovirax)Valacyclovir (Valtrex)Famciclovir (Famvir)

Management of Post herpetic NeuralgiaTricyclic antidepressants,

such as amitriptyline.Opioids, such as methadone,

morphine. Lidocaine patch.Anticonvulsants, such as

gabapentin.Capsaicin cream.Topical anesthetics, including

benzocaine.

Non-pharmacologic treatmentApply cool water

compresses to the skin or soak in a bathtub filled with cool water

Add finely ground oatmeal to the bathtub.

Apply calamine lotion to the affected areas.

Trim your fingernails to avoid infection.

Wear loose-fitting clothing.

Preventiono Shingles vaccine (Zostavax)

It is given to people 60 years of age and older who have already had the chickenpox.

The shingles vaccine is a live vaccine given as a single injection, usually in the upper arm. The most common side effects of the shingles vaccine are redness, pain, tenderness and swelling at the injection site, and headaches.

Prognosis

• Many cases of shingles go away by themselves, with or without treatment

• The rash and pain should be gone in two to three weeks

• However, shingles may last longer and be more likely to recur if the person is older, especially older than 50 years of age, or if they have a serious medical problem