Shingles is a painful skin rash caused by Varicella Zoster virus (VZV). Varicella zoster belongs to herpes virus group and thus the infection is also called as herpes zoster virus infection. Herpes virus is responsible for many other infections apart from shingles and chicken pox. Varicella zoster is a causative agent of shingles. The primary infection caused by Varicella zoster virus is also referred to as chickenpox. Varicella is known to causes two diseases in humans i.e., shingles and chickenpox.
Shingles is common in older adults and in people with a weak immune system. VZV generally enters through the respiratory tract and conjunctiva. The virus multiplies at the site of entry in the nasopharynx and in regional lymph nodes. In 4-6 days of infection the virus spreads to other organs like liver, spleen and sensory ganglia.
Primary Infection (Chickenpox)
In children the primary infection is recognised by the sudden onset of rash. Adults experience 1-2 days of fever and malaise prior to rash. Patients who have not taken the vaccination experience a generalized and puritic rash that progresses rapidly. Rashes generally appear on the head first and then on the trunk. Rashes can form lesions as the disease progresses. The lesions also appear on mucous membranes of oropharynx, respiratory tract, cornea, conjunctiva and vagina. The size of lesions varies from 1-4mm in diameter. Children generally have more than 200 lesions on their body.
When a patient recovers from primary infection, he/she is supposed to acquire lifetime immunity. Second recurrence of chickenpox is not common and very rarely the immunocompromised patients are known to face the second recurrence in their life.
Recurrent disease (Herpes Zoster or Shingles)
The recurrent infection results in shingles and is also called as herpes zoster infection. Skin lesions are commonly seen in herpes zoster infection. In recurrent stages it affects central nervous system along with pulmonary and hepatic involvement. During the recurrent phase the patient experience skin dermatomes that last for 1-10 days. The pain may stimulate headache, cardiac pain and appendicitis.
Chickenpox patients are at high risk of acquiring shingles in the later stages. Shingles is caused by a Varicella Zoster virus. Shingles occurs when the virus that causes chickenpox starts multiplying again in your body. When you recover from the primary infection or chickenpox, the virus is present in your body in a dormant state.
In some people who gain immunity the virus remains in a resting stage for lifetime. The virus starts multiplying generally in immunocompromised patients. There are certain medicines that can trigger the virus to return back to an active stage resulting in painful rash. When the virus returns to an active stage it causes only shingles and not chickenpox. Once infected with chickenpox, the patients gain lifetime immunity. The patients suffering with shingles can spread the virus to healthy person who has not had chickenpox and who has not received chickenpox vaccine.
The signs and symptoms of shingles can be classified into 3 phases:
- Pre-eruptive phase – In the initial stages you may experience headache and experience light sensitivity. In few cases flu symptoms are also seen in pre-eruptive phase
- Acute eruptive phase – Itching and pain in certain parts of the body is observed. Small band or strips of rash is seen on the body.
- Chronic phase – In chronic phase you can see large blisters on your body filled with fluid and it takes 2-4 weeks for blisters to heal completely with medication.
Shingles can be treated with medicines and can be prevented with vaccination in the early stages of life. Antiviral medicine helps in fast recovery of rashes on your body. Chicken pox patients who are above 50 years of age must take shingles vaccination to prevent the infection. Children should get vaccinated in the early stages of life to avoid the risk of shingles in the later stages. Initially you need to prevent chickenpox infection with vaccination, to avoid the complications of shingles.