Shingles causes a painful, blistering rash on one side of the body. The rash can appear in one of several places on a person’s back, such as near the shoulder blades or on the lower back near the waist.

The Centers for Disease Control and Prevention (CDC) explain that after a person recovers from chickenpox, the varicella-zoster virus remains in the body. It usually stays dormant or inactive. If the virus reactivates, it causes shingles.

In the United States, 1 in 3 people will develop shingles.

People with shingles typically develop a blistering rash on one side of the body. As the rash clears, the blisters burst and crust over. The rash usually clears within 2–4 weeks.

This article explains whether a shingles rash can appear on the back. It also describes how the rash spreads across the body, how to tell if it is shingles, and outlines other possible causes of a rash on the back.

A shingles rash can appear anywhere on the body, including the back. It usually only affects one side.

The rash can appear:

  • in a band around one side of the waistline, which can extend from the front of the torso all the way to the spine
  • in a band that extends from the front of the ribcage around to the shoulder blades
  • on the front and back of the shoulder and up to the neck

The rash typically begins on one side of the body or face in a small area.

Although it most commonly develops as a single stripe around one side of a person’s waistline, it can begin anywhere on the body. It can also affect one side of the face.

In those with weakened immune systems, the rash may be more widespread across the body. However, this is rare.

If the rash develops on the face, people should contact a doctor urgently. This is because it can affect the eye and result in vision loss.

How does the rash spread across the body?

The National Institute on Aging explains that after a chickenpox infection, the varicella-zoster virus moves from the skin to nerve cells in the spine.

There are 31 spinal nerve cells on each side of the body that branch out to send and receive sensations from the skin. Each nerve cell is associated with a particular area of skin called a dermatome. While each dermatome is associated with a single spinal nerve, there is some overlap between the zones.

The varicella-zoster virus travels along these nerve pathways, and the shingles rash usually appears in one or two adjacent dermatomes.

A shingles rash tends to center in one dermatome, but there may be odd blisters in an adjacent area if the branches of the spinal nerve cross into a different zone.

In the 1–2 days before the rash appears, people will experience burning, tingling, or pain on the area of the skin where the rash develops. This is because the virus stimulates the nerve as it travels along its pathway.

Once the virus reaches the skin, it forms a rash.

A shingles rash usually begins as groups of tiny pimples that spread to form a band or stripe. These pimples then fill with pus and form blisters.

The CDC notes these blisters usually scab over within 7–10 days, with the rash clearing completely within 2–4 weeks.

The most distinctive feature of a shingles rash is that it only appears on one side of the body. Other symptoms include:

Shingles is not the only cause of a rash on the back. Other possible causes include:

  • Lichen planus: This is a skin condition that causes shiny, firm bumps. They often appear on the lower back and can also commonly affect the wrists and ankles. A person with lichen planus can develop blisters, but these are rare.
  • Poison ivy: A person can develop a blistering rash on the area of skin that comes into contact with the plant. A poison ivy rash may take 2–3 weeks to appear after contact with the plant if the person has not previously had a reaction. Before the rash appears, the area of affected skin will itch intensely.
  • Contact dermatitis: This occurs when the skin comes into contact with a substance that results in an allergic reaction or irritates the skin. People will develop scaly, inflamed skin.
  • Bullous pemphigoid: This is a rare skin condition that affects older adults. The rash is itchy and raised, and blisters develop as the condition develops.
  • Reaction to medication: Some people develop blisters around their eyes after taking medications. The rash can be painful and develop alongside a fever.

Anyone with a blistering rash should consult a doctor as soon as possible.

Doctors can prescribe antiviral medications for shingles. If a person takes these medications within 2–3 days after developing the rash, this can:

  • ease the pain
  • shorten the infection time
  • reduce the risk of developing complications

Doctors treat shingles with antiviral medications. These include:

Over-the-counter pain medicines and calamine lotion may also help reduce the itchiness.

People with shingles on the back have an itchy, blistering rash that affects one side of the body.

The rash can develop anywhere but most commonly appears in a strip around the waistline. Shingles can also develop on the back.

If a person notices symptoms of shingles, they should contact a doctor urgently.