Postherpetic neuralgia (PN) is a chronic complication of herpes zoster
(shingles), which affects the nerves. Herpes zoster results from reactivation
of dormant viruses in the sensory ganglion and is manifested by acute,
painful vesicular rash over a single dermatome (nerve region). The varicella-zoster
virus (VZV) is a nerve virus that gains access to neurons during a childhood
infection of chickenpox (varicella). More than 95% of young adults are
seropositive for VZV, and the incidence rate is 3.4 cases per 1,000 persons.
Patients often have chest wall pain before an outbreak of shingles. With
this condition, patients have itching, numbness, and a rash. Once the
rash dries up, the pain may continue. The pain can be spontaneous (burning
and ongoing), paroxysmal shooting or electric shock-like pain, or the
patient may experience evoked sensations in response to light touch or
other mechanical stimuli. The type and intensity of pain vary from patient-to-patient.
Postherpetic neuralgia also affects the quality of life and sleep. Patients
often report a much pain and suffering due to the condition, which can
lead to loss of sleep. Functional status is also affected by the pain,
with a limited range of movement of the chest region due to the discomfort.
Duration of Postherpetic Neuralgia
So how long does postherpetic neuralgia last? Researchers are unsure what
triggers the herpes zoster virus to re-emerge after years of lying dormant.
The virus may be obtained during youth but it will not flare into shingles
until years down the line. The pain of shingles usually persists for around
three months. When this pain lingers long after the rash heals, it is
The bout of shingles damaged the nerves. This means that the nerve damage
caused by shingles brings on a fully functioning nervous system. The damaged
nerve will send random pain signals to the brain, and it causes a burning,
throbbing sensation. Over time, the nerves of the skin calm, but with
the nerve damage existing, the pain can persist for years, even for the
remainder of a person’s lifetime.
Postherpetic Neuralgia Treatment
- There is currently no disease-modifying therapy for PN. Treatment is based
mainly on symptom control. Because pain may persist for years, or for
the remainder of life, medication is often used over prolonged periods.
Randomized controlled trials support the use of topical and oral agents
to treat PN.
• Topical treatment – Topical therapy is the first-line treatment
for mild pain. It is used in combination with systemic drugs when pain
is moderate or severe. The patches have 5% lidocaine, which is an analgesic
agent. In a meta-analysis of studies, this treatment offered patients
at least 50% pain relief. Capsaicin cream also has proven effective. It
must be applied several times daily and is proven effective as a low-concentration patch.
• Systemic treatment – Certain drugs are used for nerve-related
pain. For PN, drugs proven effective are tricyclic antidepressants and
antiepileptics. In many studies, amitriptyline, nortriptyline, and desipramine
were shown to help treat. Gabapentin and pregabalin are two anticonvulsants
that appear to offer some
benefit in the treatment of postherpetic neuralgia.