<unk>  <unk>  is neuropathic pain that occurs due to damage to a peripheral nerve caused by the reactivation of the varicella zoster virus (herpes zoster, also known as shingles). Typically, the nerve pain (neuralgia) is confined to an area of skin innervated by a single sensory nerve, which is known as a dermatome.<unk>  is defined as dermatomal nerve pain that persists for more than 90 days after an outbreak of herpes zoster affecting the same dermatome. Several types of pain may occur with<unk>  including continuous burning pain, episodes of severe shooting or electric-like pain, and a heightened sensitivity to gentle touch which would not otherwise cause pain (mechanical allodynia) or to painful stimuli (hyperalgesia). Abnormal sensations and itching may also occur. The nerve pain of<unk>  is thought to result from damage in a peripheral nerve that was affected by the reactivation of the varicella zoster virus or troubles after chemotherapy.<unk>  typically begins when the herpes zoster vesicles have crusted over and begun to heal, but can begin in the absence of herpes zoster—a condition called zoster sine herpete. There is no treatment that modifies the disease course of<unk> ; therefore, controlling the affected person's symptoms is the main goal of treatment. Medications applied to the skin such as capsaicin or topical anesthetics (e.g., lidocaine) are used for mild pain and can be used in combination with oral medications for moderate to severe pain. Oral anticonvulsant medications such as gabapentin and pregabalin are also approved for treatment of<unk> . Tricyclic antidepressants reduce<unk>  pain, but their use is limited by side effects. Opioid medications are not generally recommended for treatment except in specific circumstances. Such cases should involve a pain specialist in patient care due to mixed evidence of efficacy and concerns about potential for abuse and addiction.<unk>  is the most common long-term complication of herpes zoster. The incidence and prevalence of<unk>  are uncertain due to varying definitions. Approximately 20% of people affected by herpes zoster report pain in the affected area three months after the initial episode of herpes zoster, and 15% of people similarly report this pain two years after the herpes zoster rash. Since herpes zoster occurs due to reactivation of the varicella zoster virus, which is more likely to occur with a weakened immune system, both herpes zoster and<unk>  occur more often in the elderly and in people with diabetes mellitus. Risk factors for<unk>  include older age, a severe herpes-zoster rash, and pain during the herpes zoster episode.<unk>  is often very painful and can be quite debilitating. Affected individuals often experience a decrease in their quality of life.
Postherpetic neuralgia
Trigeminal neuralgia
Atypical trigeminal neuralgia
Occipital neuralgia
Erythromelalgia
Morning sickness
Cold-stimulus headache
Cerebritis