As the rash first appeared,on the left side of the chest.

Early stage of shingles
on back and side

Herpes zoster is commonly known Shingles, the name being derived from the Latin word Cingulum meaning a girdle or band reflecting the band like distribution of the painful rash which encircles one side of the body.
It is caused by the varicella-zoster virus which earlier in life causes chicken-pox, but may lie dormant in some nerve roots of the spinal cord for years before being activated when disease, stress or old age lower the body’s immunity.
Pop-Star had chicken-pox when he was 12.  “Monoclonal B cell lymphocytosis“, an early asymptomatic form of chronic lymphocytic leukaemia may have affected his immunity.
Since the virus spreads along the nerves damaging them, it causes constant painful sensations which range from a constant ache, sharp stabbing pains, creepy crawly feelings, a painful itch, at times  hot boring pain, and intense sensitivity.

 
Since it is not often life-endangering, it is a condition that is not particularly news-worthy; but it can plague the lives of the elderly for a long time, at a time when their health is already compromised.
In the early stages of the rash when little vesicles or blisters are forming, the patient may pass on the virus to others, but surprisingly, if infected chicken-pox not shingles is the outcome.

Shingles can involve almost any region of the body, but most commonly the chest or the abdomen. Less commonly the trigeminal nerve of the face can be involved. The characteristic features of the condition are that the rash is painful and always confined to just one side of the body.

Fully developed area on the back

Fully blown rash left chest

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