Herpes Zoster (Shingles) - Causes, Symptoms, Treatment, and Prevention

Introduction - Herpes Zoster (Shingles)

Herpes zoster is also known as shingles, caused by the reactivation of the varicella-zoster virus, the same virus that causes chickenpox.

It is an acute viral infection of the nerve cell and surrounding skin, characterized by very painful rash of blisters,  but it is not life-threatening.

Shingles caused by the Varicella-Zoster virus that same virus that causes chickenpox (varicella). Shingles is a viral infection that causes a painful rash with blister.

The Shingles usually appears, 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.

 Causative Agent- Varicella Zoster virus (DNA Virus)

Varicella-Zoster virus (VZV) infection cause two clinically distinct forms of diseases –

1. Chickenpox (varicella)

2. Herpes zoster (shingles)

Primary infection results in varicella (chicken pox) and Recurrent infection results in herpes zoster (shingles)

 Shingles Epidemiology

1. Transmission

Direct contact with open sores of shingles rash

Infect to someone who has never had the Chicken pox.

Skin to skin contact with blisters are contagious

2. High incidence group

Anyone who had chicken pox.

People over the age of 50

 

Incubation period

The incubation period of herpes zoster (shingles) usually 14 to 16 days (range of 10-21 days)

 Pathophysiology of Herpes Zoster (shingles)

1. Varicella zoster virus (VZV) enters through the respiratory track

 2. Viral replication in regional lymph nodes

 3. Primary viremia in blood stream

 4. Further viral replication in liver and spleen

 5. Secondary Viremia

 6. Enter into nerve endings and transport of dorsal root ganglia (DRG), Part of  spinal cord, where it lies DORMANT in sensory nerve ganglia dorsal root.

 7. Reactivation in dorsal root ganglia

8. Infection of nerve and dermatome (area of skin that's supplied by a single spinal nerve)

 9. Lead to Herpes zoster

 

Causes and Risk Factor of Herpes zoster

1. Age- Shingles is most common in people older than 50 years age. The risk of infection increases with age.

2. Cancer treatment- Undergoing radiation or chemotherapy n lower the resistance to disease and may trigger shingles.

3. Immunosuppressant drugs- prolonged use of steroids such as prednisone

4. Having certain diseases HIV/AIDS- Diseases that weaken immune system, such as HIV/AIDS, can increases risk of shingles.

 

Clinical Symptoms of Shingles

1. Initial prodromal stage

The first sign of shingles may include-

1. Headache

2. Feeling generally unwell

3. Myalgia (pain in muscle or group of muscle) 

4. Fever

5. Fatigue

6. Malaise

 

2. Acute stages

1. A rash will begin to develop often causing a pain and burning.

2. Itching or tingling sensation or sensitivity to touch in the area of the affected nerve.

3. A fluid filled blister painful rash develops a few days after and commonly occurs on chest and abdomen, but it can appear on face, eyes.

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

Know the signs and symptoms of Chickenpox and pathophysiology of chickenpox

Complications of Herpes Zoster (shingles)

1. Post - herpetic neuralgia (PHN)  

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

2. Ophthalmic shingles 

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

3. Ramsay hunt syndrome 

known as herpes zoster oticus, inflammation of several of the nerves that come out of the brain. The symptoms of Ramsay hunt syndrome are facial ear pain, haracterized by paralysis of the facial nerve (facial palsy) and a rash affecting the ear or mouth.

4. Encephalitis

5. Ear symptoms 

Hearing problem, Shingles can also occur in or around the ear, leading to problems with balance and hearing.

6. Bacterial infection on skin - If shingles blisters aren't properly treated, bacterial skin infections may develop.

7. Eye symptoms - Cranial nerve involvement (Herpes Zoster Ophthalmicus) - painful inflammation of the tissues of  of the eye.

8. Mouth symptoms - If shingles affects the mouth, it can cause  facial tenderness, pain in the mouth, toothache, lesions in hard and soft palate tissues.

 

Shingles Diagnosis

1. Skin sample- Infected with varicella-zoster viruses                                                            

2. Blood test - Increase in white blood cells

 

Management of Acute Herpes Zoster

1. Antiviral medication

To reduce the pain and complications should be stored with in 24 hours of first symptoms. These medication include-

1. Acyclovir (zovirax)

2. Valacyclovir (valtrex)

3. Famciclovir (famvir)

Post herpetic neuralgia is most common complication of shingles. 

Management of Post Herpetic Neuralgia

1. Tricyclic antidepressants, such as Amitriptyline

2. Opioids such as methadone, morphine

3. Lidocaine patch

4. Anticonvulsants

5. Capsaicin cream

6. Tropical anaesthetics include Antidepressants.

7. Benzocaine

Non- Pharmacological Treatments

1. Apply cool water compresses to the skin or soak in bathtub filled with cool water. Daily cleansing of the blisters can reduces the risk of spreading the infection and coolness of the water can relieve from pain from shingles blisters and calm itchiness.

2. Add finely ground oatmeal to the bathtub

3. Apply Soothing lotions and creams – Apply calamine lotion to the affected areas

4. Trim your fingernails to avoid infection

5. Wear loose- fitting clothing

6. Apply herbal remedies – such as Neem leaves

 

Prevention of Shingles

1.  Shingles vaccine

Zostavax and Shingrix – it is given to people 60 years of age and older who have already had the chickenpox.

Zostavax (zoster vaccine live) - 0.65-mL is administered subcutaneously as a single dose in the deltoid region.

The shingles vaccine is 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 injection site and headaches.

 

Prognosis of Shingles

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

2. The Rash and pain should be gone in 2 to 3 weeks, usually resolves within 10-15 days.

3. Elderly people, especially older than 50 years of age have a increased risk of complications. Shingles may last longer and be more likely to recur (occur again), if they have a serious medical problem.

4. Inflammation can affect the soft tissue under and around the rash area of skin.