B00-B09: Viral infections characterized by skin and mucous membrane lesions

B02: Zoster [herpes zoster]

Zoster, commonly known as herpes zoster or shingles, is a group of conditions caused by the reactivation of the varicella-zoster virus, the same virus that causes chickenpox. When a person gets chickenpox, the virus does not completely leave the body. Instead, it stays dormant in nerve tissues and can reactivate years later, causing herpes zoster. The condition typically presents as a painful skin rash with blisters, often in a band around one side of the body or face. Common symptoms include pain, itching or tingling, fever, headache, and fatigue. The progression of the disease can also involve complications such as post-herpetic neuralgia, where the pain persists long after the rash has healed. The condition primarily affects the integumentary system (skin) and the nervous system, and it is more common in older adults and in those with weakened immune systems.