Postherpetic neuralgia is a complication that can develop after suffering from a bout of shingles. Shingles, also known as herpes zoster, is the reactivation of the chickenpox virus. It generally affects those who are older in age or have poor immune function. Shingles typically presents as a single, band-like painful rash on one side of the face or body. The rash will generally resolve in two to four weeks and is treated with antiviral and pain medications.