Shingles: Is It Contagious and What Causes It

Shingles is an infection that causes a painful rash, and it does not itself pass from a sick person to a healthy one. However, the virus that causes it is the same one that causes chickenpox, so contact with the rash is dangerous for those who have never had chickenpox. Below is what is known about contagiousness, causes, and signs of the disease.

What shingles is and how it relates to chickenpox

Shingles (herpes zoster) is a viral infection with a painful rash caused by the varicella-zoster virus (Varicella zoster). On first contact with the body, this virus causes typical chickenpox. After the illness, it remains in the nerve ganglia in a latent state and can become active later. According to various estimates, herpes zoster occurs in approximately 10–20% of cases of chickenpox. Despite the word "herpes" in the name, this is a different virus from the one that causes "cold sores on the lips."

Whether shingles is contagious or not

Shingles is not contagious: you cannot catch it from another person. However, a person with shingles can transmit the chickenpox virus to someone who has not previously had chickenpox and has not been vaccinated — and that person will develop chickenpox. The risk of transmission is low if the rash is covered. A sick person does not spread the virus before the blisters appear or after the rash has crusted over. While the blisters are weeping and cannot be covered, it is recommended not to go to work or school.

How the virus is transmitted and who can become infected

Infection is possible from a person with herpes zoster or chickenpox. The routes of transmission are airborne and contact, and a transplacental route is also possible. Someone who has not had chickenpox and has not been vaccinated can catch chickenpox from a person with shingles. Extra caution is needed around people with weakened immunity, pregnant women who have not had chickenpox in the past, and infants under one month of age.

What causes shingles: causes and risk factors

The disease occurs when the virus reactivates against a background of reduced immunity. Common causes include taking medications that suppress the immune system, chronic stress and exhausting work, local hypothermia, cancer, the effects of radiation therapy, HIV infection, and organ and bone marrow transplantation. The risk is higher in people over 50–55 years of age, in pregnant women, and after prolonged treatment with antibiotics, cytostatics, and glucocorticosteroids. Recurrent cases are possible: about 2% among people with normal immunity and up to 10% with immunodeficiencies.

How the disease manifests and how it is recognized

First, tingling, itching, or pain appears in an area of skin, sometimes with malaise and fever. After a few days, a rash appears — usually on one side of the body, more often on the trunk, but it can occur on the face, eyes, and other areas. The spots turn into itchy fluid-filled blisters that dry out and crust over after 6–8 days. A rash on both sides of the body is atypical for shingles. The diagnosis is usually made by examination and history-taking; in some cases, a scraping from the rash or a swab of fluid from the blisters is taken for laboratory testing.

• pain and tingling before the rash appears
• rash on one side of the body
• blisters that weep and then crust over
• headache, chills, and upset stomach are possible

When to see a doctor

It is best to see a doctor as early as possible — in the first days after the rash appears, since timely care reduces the risk of long-term problems. Special attention is required for pregnant and breastfeeding women, people with significantly weakened immunity, and cases where the rash affects the eye or nose or vision changes. The doctor assesses the severity of symptoms and the risk of complications and, if necessary, prescribes testing.

This alone is not a reason to call an ambulance; 103 or 112 — if signs of a severe condition appear against the background of the illness: marked weakness, confusion, difficulty breathing, or rapid deterioration.

This material is for reference: it explains general principles and does not replace consultation with a doctor, who will assess your situation individually.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer