Shingles can occur many times - recurrent, chronic. Shingles can last a long time.
I had shingles once on my back. Now many years later I have had shingles for 3 years on the crown of my head and the rash has never gone away. I have seen 15 doctors. After 7 doctors, I insisted they do a biopsy as they told me it could not be shingles -- since shingles does not last this long and can only exist on one side of the body. The biopsy confirmed active herpes zoster rash which had been in existence for 1 1/2 years. I still have this rash. The biopsy testing was extensive and nothing else was found (no lupus or other auto-immune disease etc.). It is Shingles.