Shingles is a viral infection caused by the same virus that causes chicken pox, the varicella-zoster virus [VZV]. Shingles is characterized by a painful, patchy skin rash with small blisters.

It may affect many different body parts depending on which dermatomes (the area of the body supplied by a spinal cord nerve) are involved. Shingles tends to be more painful and cause less itching than chickenpox.  

In most cases, the dominant symptom is extreme sensitivity or pain along specific bands of nerves on one side of the body. It is sometimes accompanied by other vague symptoms, such as numbness, tingling and itching. In some cases shingles is painless. This is more common in children.

Two to five days following the initial sensation, a rash consisting of red blisters appears on the surface of the skin in the same location. The blisters then break, forming small ulcers that dry and crust over. The rash usually lasts about two or three weeks before it scabs and disappears, sometimes leaving pink or scarred skin.

Rash blisters or lesions most often appear along a single dermatome, and on only one side of the body, though two or three adjacent dermatomes may occasionally be involved. The thoracic (chest) and lumbar (lower back) dermatomes are most often affected by shingles. The cervical (neck) and ophthalmic (forehead) dermatomes are commonly affected as well. Some patients may develop a few scattered blisters on the body separate from the rash. This occurs when small amounts of VZV are released from the affected nerve areas into the bloodstream and spread to other locations. In general, blisters tend to be deeper in elderly patients.

Blisters that occur in the mouth or eye can lead to permanent blindness if left untreated and require immediate medical attention. In addition, involvement of the facial nerve may cause serious side effects (e.g., facial paralysis, hearing loss). These effects may be temporary or permanent.

In most cases, the skin returns to normal and the pain subsides after four to five weeks. However, some patients may experience post-herpetic neuralgia, a condition in which the pain from shingles lasts for months or years after the lesions disappear. The lasting pain may be minor but is more often severe in nature. A slight breeze blowing past the skin or a light sheet touching the skin can cause extreme pain. In some cases, the condition produces persistent itching instead of pain.  

Other signs and symptoms that may be experienced either prior to or during an outbreak of shingles include:

• Fever
  
  
• Headache
  
  
• Enlarged and tender lymph nodes
  
  
• Muscle weakness
  
  
• Chills
  
  
• Upset stomach

Individuals who suspect shingles should promptly contact a physician. Treatment methods are much more effective when started early.