Shingles is a viral infection caused by the reactivation of the varicella-zoster virus (VZV), the chickenpox virus. After chickenpox, VZV remains inactive in nerve cells, reactivating later to cause shingles, a painful skin rash.
The Prodromal Phase
The prodromal phase is the initial stage, occurring before any visible rash. Individuals may experience pain, tingling, burning, or itching in a specific body area, often localized to one side of the body or face, following nerve pathways. This phase typically lasts one to five days.
The Active Rash Phase
After prodromal symptoms, the active rash phase begins with visible skin changes. Red patches and bumps (macules and papules) first appear where earlier sensations were felt. This rash commonly forms a distinct band or strip on one side of the body (torso, neck, or face), following a nerve path (dermatome). Appearance varies, from red on lighter skin tones to purple, pinkish, or brown on darker skin tones.
The Blistering Phase
As the rash progresses, bumps transform into fluid-filled blisters (vesicles), a hallmark of the blistering phase. These are often painful and sensitive to touch, typically forming in clusters within the affected skin. The fluid inside contains the varicella-zoster virus, making the rash contagious until crusted over.
The Crusting and Healing Phase
The final visible stage involves the rash’s drying and healing. Fluid-filled blisters flatten, dry out, and form scabs or crusts. These scabs eventually fall off, allowing the skin to heal. The entire process, from rash appearance to scabs clearing, typically takes two to four weeks. Temporary skin pigmentation changes or minor scarring can sometimes occur.
Post-Shingles Considerations and Management
Postherpetic Neuralgia (PHN)
Even after the rash clears, some individuals may experience persistent nerve pain, known as postherpetic neuralgia (PHN). This pain (aching, burning, sharp, or shooting) occurs where the rash was located and can last weeks, months, or years. PHN affects 10% to 18% of shingles patients, with older individuals more susceptible.
Other Complications
Other complications include scarring or, if the rash affects the face or near the eye, serious eye involvement (inflammation, corneal scarring, glaucoma, or vision loss). Prompt medical attention is important if shingles develops near the eye.
Treatment
Treatment for shingles often includes antiviral medications like acyclovir, valacyclovir, and famciclovir. Most effective within 72 hours of rash onset, these medications can reduce outbreak severity and duration and lessen PHN risk. Pain relief strategies, including over-the-counter pain relievers, are also used.
Prevention
Shingles prevention is primarily achieved through vaccination. The Shingrix vaccine is recommended for healthy adults aged 50 and older, and those 19 and older with weakened immune systems. Shingrix is a two-dose series, demonstrating over 90% effectiveness in preventing shingles and significantly reducing PHN risk. It is the only shingles vaccine available in the U.S., preferred over the older, discontinued Zostavax vaccine.