I. An "Aftershock" That Seems to Have Healed: Do You Understand Postherpetic Neuralgia in the Head and Face?

1. The rash is gone, but the pain "refuses to leave"
Many people assume that once the blisters crust over and the rash fades, shingles is over. However, for a considerable number of patients, the disappearance of the rash does not mark the end of suffering—the pain not only persists but may even intensify.

Postherpetic neuralgia (PHN) in the head and face refers to neuropathic pain that continues for more than one month after the shingles rash in that region has healed. This pain is fundamentally different from the nociceptive pain of the acute phase—it is not the skin "crying out," but rather a malfunction of the nervous system itself.

Epidemiological studies show that approximately 9% to 34% of shingles patients develop PHN. Among those aged 60 and above, the proportion is even higher—about 50% to 75% of elderly patients may experience PHN. The pain can last from several months to several years, and in some individuals, it may persist for more than a decade.

2. The head and face: the most "challenging" site
PHN in the head and facial region accounts for a significant proportion of all PHN cases and is one of the most complex areas to manage. When the virus invades the trigeminal nerve (especially the ophthalmic branch), the situation becomes particularly intricate.

The head and face are densely innervated, with the trigeminal, facial, and occipital nerves interwoven into a complex network. Once these nerves are attacked by the virus, the pain is not only severe but also widespread—from the forehead, eye sockets, and cheeks to the jaw, periauricular area, and occipital region can all become "battlefields" of pain. Patients may experience stabbing or electric‑shock‑like pain triggered by routine actions such as combing hair, wearing a mask, or even a breeze on the face.

II. Where Does the Pain Come From? Unveiling the Pathophysiology of PHN in the Head and Face

1. The vicious cycle of viral "latency–reactivation"
The culprit behind shingles is the varicella‑zoster virus. Most people contract chickenpox in childhood; the virus then establishes latency in the dorsal root ganglia or cranial nerve ganglia, entering a dormant state. When the immune system weakens—due to fatigue, illness, aging, or use of immunosuppressants—the latent virus may reactivate.

The virus travels along sensory nerve fibers to the skin, causing the characteristic rash and blisters. But the problem extends far beyond the skin lesions—during this journey, the virus inflicts substantial damage to sensory ganglia and nerve fibers.

2. Nerve "denuding" and "short‑circuiting"—the biological basis of pain
Why does nerve pain persist even after the rash has healed? Modern medical research has found that the varicella‑zoster virus is neurotropic and attacks the myelinated coarse fibers in nerve sheaths. When the myelin sheath is stripped away, the nerve axon (inner core) becomes exposed—much like an electrical wire losing its insulation.

These "denuded" nerves become hypersensitive—light touch, temperature changes, or even a puff of air can trigger abnormally intense neural discharges, perceived by the patient as electric‑shock‑like, stabbing, or burning pain.

More complex still, this damage induces both "peripheral sensitization" and "central sensitization." Peripheral sensitization makes the damaged nerve endings hyper‑reactive, so that mild stimuli produce intense signals; central sensitization turns up the "volume" of pain signals in the spinal cord and brain. Under this dual effect, pain is continuously amplified and prolonged.

III. Typical Symptoms and Impact on Daily Life of PHN in the Head and Face

1. The "many faces" of pain
Pain in PHN of the head and face is highly diverse. Patients may experience:

• Burning pain: as if fire is smouldering beneath the skin

• Electric‑shock‑like pain: sudden, fleeting, sharp jolts

• Stabbing or cutting pain: persistent or intermittent sharp sensations

• Throbbing pain: pulsating in time with the heartbeat

Many patients experience multiple types of pain simultaneously, and the painful area is often larger than the original rash distribution.

2. Allodynia: the most "torturous" feature
One of the most classic and distressing characteristics of head‑and‑face PHN is allodynia—pain triggered by normally innocuous stimuli. Combing hair, washing the face, wearing a mask, friction from a pillow, or even a light breeze can evoke stabbing or burning agony. Patients are forced to move cautiously, avoiding any potential contact.

3. More than just physical pain
The impact of head‑and‑face PHN on quality of life extends far beyond the pain itself. Studies show that approximately 45% of patients experience moderate‑to‑severe emotional disturbance, manifesting as anxiety, depression, and difficulty concentrating. Over 40% have moderate‑to‑severe sleep disorders. Some research reports that about 60% of patients have had suicidal thoughts at some point.

Under the relentless assault of severe pain, patients not only suffer from low mood but also experience significant impairment in work and social functioning. Adding to the distress, because the skin surface may appear normal, patients are often misunderstood by family members—"Your skin looks fine, why do you keep complaining about pain?"

IV. Facing PHN in the Head and Face: What Are the Options?

PHN in the head and face is globally recognized as one of the most challenging pain disorders. Notably, traditional Chinese medicine (TCM) has demonstrated unique approaches and methods in this field. TCM external therapies, based on the principle of "expelling pathogenic factors outward," are applied directly to the painful area, aiming to clear the "toxic pathogens" that irritate the nerves.

Among these, the Five‑linked Anti‑drug Pain Therapy—a comprehensive TCM external treatment—has been specifically designed and applied for head‑and‑face PHN. This therapy uses a synergistic combination of professionally formulated medicinal solutions and agents, applied in a targeted manner to the affected region. For patients without serious underlying conditions, and provided that both the patient and their family strictly adhere to the prescribed contraindication instructions, most patients experience improvement or gradual resolution of pain within 3 to 8 treatment sessions.

Treatment outcomes vary from person to person and are influenced by individual differences, disease duration, underlying health conditions, and other factors. Please consult a qualified healthcare professional for proper evaluation and guidance.