Causes
The latent or "quiet" infection caused by varicella-zoster can
become active again, even many years after you've had chickenpox. This can
occur when your immune system isn't working at its best. This may be due to
any of the following reasons:
- older age
- illness
- use of drugs that suppress the body's immune system (e.g., corticosteroids
for severe asthma)
- HIV infection or certain types of cancer
- radiation treatment
Shingles rarely occur in children under the age of 10. The risks of getting
it at that age increase significantly if a child has been infected with the
virus during the first year of life, or if the mother had chickenpox during
pregnancy.