The Centers for Disease Control and Prevention estimates that about 50 percent of Americans who live to 85 years of age have had shingles at some point. The disease results when the varicella-zoster virus--the same virus that causes chickenpox--reawakens in clusters of sensory nerves near the spinal cord, called the dorsal root ganglia. Although the trunk and back are the most commonly involved areas, the head is sometimes affected.
Shingles causes a rash that begins as red, swollen patches of skin that evolve--over a few hours--into 5- to 10-mm fluid-filled blisters. New lesions develop in crops for three to five days. In healthy people, these lesions rupture and crust between seven to 10 days, signaling the end of the infectious phase of the disease. However, two to four weeks may be required for complete healing. In the case of head shingles, these lesions appear on the scalp, face, mouth ears, and eyelids. When shingles affects the eye itself, it can result in permanent changes in vision or even blindness.
Many people with head shingles complain of systemic symptoms such as fever, headache, sensitivity to light, decreased appetite and an overall sense of malaise. People often mistakenly believe they are coming down with the flu or a cold. However, characteristic respiratory symptoms of these infections, such as dry cough and runny nose, never appear. Fever due to head shingles is typically low grade or even subjective. A person feels feverish, although the temperature measures as normal. Symptoms usually start a few days before skin lesions appear on the head; they resolve when skin lesions crust or scab over.
Pain due to head shingles begins as mild tingling, burning, itching, stinging or soreness in the areas where lesions later appear. When lesions actually appear, pain worsens and may even be disabling. Pain may be set off by facial movements or even light touch, such as a faint breeze. For most people, pain resolves within one to two months, however for some patients, pain persists even longer. This condition is known as post-herpetic neuralgia.
In some people with head shingles, the disease turns inward, causing encephalitis: inflammation in the brain. Symptoms include fever, headache, sensitivity to light and vomiting. A key difference between brain inflammation and flu-like illness is that the latter presents gradually; symptoms due to brain inflammation start suddenly. Brain inflammation is also progressive. Patients soon demonstrate signs and symptoms that are clearly neurological, such as muscle weakness, poor coordination, lethargy, mental confusion and irritability. Without prompt initiation of antiviral drugs and steroids, patients may develop seizures or coma.