Postherpetic neuralgia

A painful blistering skin rash caused by the chicken pox virus; also known as shingles.

A family of viruses which cause a range of infections including chickenpox (Herpes zoster, or varicella), cold sores and genital herpes (Herpes simplex).

A micro-organism which invades living cells in order to grow or reproduce. Viruses cause many infections, from the common cold, chickenpox and measles to HIV.