Shingles is a viral infection caused by the varicella-zoster virus, the same pathogen responsible for chickenpox. After an initial chickenpox infection, the virus remains inactive within nerve tissues. Years or decades later, this dormant virus can reactivate, leading to shingles, which can manifest on the scalp.
How Shingles Affects the Scalp
Shingles develops when the dormant varicella-zoster virus reactivates within nerve tissues. The virus travels along specific nerve pathways, known as dermatomes, which are areas of skin supplied by a single spinal nerve. When the virus affects cranial nerves, such as the trigeminal nerve that innervates the scalp and face, shingles can appear in these regions.
The characteristic rash appears unilaterally, affecting only one side of the head or face. This pattern follows the path of the affected nerve. The virus causes inflammation in these nerves, resulting in various symptoms along the pathway.
Recognizing Scalp Shingles Symptoms
Initial signs of shingles on the scalp often precede any visible rash, presenting as localized burning, tingling, numbness, or sharp pain. This can occur several days before the rash appears. People may also experience headache, fever, or fatigue during this prodromal stage.
Within one to five days after these initial sensations, a rash of fluid-filled blisters usually emerges on the scalp or other affected areas. These blisters often cluster together in a band-like pattern following the nerve pathway. The rash can vary in appearance, showing as red on lighter skin tones and purple or grayish on darker skin.
As the rash progresses, the blisters may ooze and then dry up, forming yellowish scabs, which takes 7 to 10 days. The entire shingles episode lasts three to five weeks. Increased sensitivity to touch in the affected area is also common, and scratching the blisters can lead to secondary bacterial infections or scarring.
Treatment and Potential Complications
Early diagnosis and prompt treatment are important for managing shingles on the scalp and reducing complications. Antiviral medications, such as acyclovir, valacyclovir, and famciclovir, are commonly prescribed. These medications are most effective when started within 72 hours of rash onset, as they reduce symptom severity and duration.
Other management strategies include pain relief using over-the-counter medications like acetaminophen or ibuprofen, or prescription pain relievers for severe discomfort. Applying cool compresses to the affected area can lessen pain and itching. Keeping the rash clean and avoiding scratching helps prevent secondary bacterial infections.
Shingles on the head and scalp carries a risk of specific complications due to proximity to vital structures. Postherpetic neuralgia (PHN) is the most common complication, characterized by persistent nerve pain that can linger for months or even years after the rash has cleared. This pain can be debilitating and interfere with daily activities.
If the virus affects the trigeminal nerve branch leading to the eye, it can result in ophthalmic zoster, a serious complication that may cause vision problems, including keratitis, uveitis, or even permanent vision loss. Hutchinson’s sign, the appearance of lesions on the tip of the nose, can indicate an increased likelihood of eye involvement. Another potential complication is Ramsay Hunt Syndrome, which occurs if the virus affects the facial nerve. This can lead to facial paralysis on one side, ear pain, hearing loss, and blisters in or around the ear. Prompt medical attention for suspected shingles, especially on the head or face, is advisable to reduce the risk of these serious complications.