February 9, 2023

Shingles or herpes zoster is an infection characterized by severely painful skin eruptions and blisters. It is caused by the virus varicella zoster. After an initial infection, which may be asymptomatic or in the form of chickenpox, the virus enters nerves and stays dormant or inactive for years. It becomes reactivated; in most cases the cause is unknown.
In some cases, the virus becomes active again if a person’s immune system becomes weak. This is seen in situations like when a person is on medications to treat cancer or autoimmune disorders like systemic lupus erythematosus to prevent rejection after organ transplantation, or suffers from HIV and other infections that compromise the body’s innate protective responses to infections, or have diseases that weaken the immune system like leukemia (cancer of the blood) and lymphoma (cancer of the lymph nodes).
Spinal or cranial nerves are affected, and the skin lesions follow the distribution or dermatomes of the nerve roots involved. Three to four days before lesions develop, one may have body malaise, chills, fever, nausea, loose bowel movement, or some difficulty in urination. There may be tingling or burning sensation, pain, numbness, or skin itchiness. Small groups of blisters develop and these are surrounded by reddish areas. Blisters eventually erupt after five days then drying and scab formation occurs. The body area affected becomes sensitive even to slightest touch and pain is a characteristic feature of the illness.
Shingles by itself is not contagious – the rashes are not spread to other persons. However, the blisters contain the varicella zoster virus and when these blisters erupt the virus may be transmitted through direct contact to persons who are susceptible – those without history of natural infection or without prior immunization. Once scabbing and drying up occurs, the skin lesions are not likely to be a source of the virus.
What happens when a susceptible person gets infected with the virus? Herpes zoster or shingles itself does not develop, and the person may develop chickenpox, or the person may just be asymptomatic and the virus may just stay in nerves – becomes dormant – and cause herpes zoster when reactivated.
Herpes zoster usually affects persons above 50 years old but it can occur in any age. If a person is immune-compromised, the blisters may persist for two weeks or more or may involve larger areas of the skin. Serious complications may occur if the nerves of the face are affected because of their close proximity to the brain. Postherpetic neuralgia – pain that persists longer more than one to three months after the rashes have resolved – is a common complication.
The virus cannot be eliminated by drugs. Treatment is geared towards treatment of the acute viral infection, analgesia or pain control, and prevention of postherpetic neuralgia. The duration of blister eruption may be shortened and the pain may be lessened by antiviral drugs like acyclovir, famciclovir, and valaciclovir – best started within three days after the onset of the rashes.
Lifelong immunity develops in most persons who had shingles and further infections occur in only less than four percent.