Summary about Disease
Varicella Zoster Virus (VZV) causes two distinct diseases: chickenpox (varicella) and shingles (herpes zoster). Chickenpox is a highly contagious, acute illness characterized by a widespread, itchy, blister-like rash. After the chickenpox infection resolves, the virus remains dormant in nerve cells. Shingles is a reactivation of this dormant virus, causing a painful, localized rash, typically on one side of the body.
Symptoms
Chickenpox: Itchy, blister-like rash that appears all over the body, fever, fatigue, loss of appetite, headache.
Shingles: Pain, burning, tingling, or numbness on one side of the body, followed by a rash of blisters in the same area. The rash is usually limited to a single dermatome (an area of skin supplied by a single nerve). Other symptoms may include fever, headache, chills, and fatigue.
Causes
Chickenpox: Caused by initial infection with the Varicella Zoster Virus (VZV).
Shingles: Caused by the reactivation of the dormant Varicella Zoster Virus (VZV) in nerve cells. Reactivation can be triggered by factors such as weakened immunity, stress, or aging.
Medicine Used
Chickenpox: Antiviral medications (e.g., acyclovir, valacyclovir) may be used, especially in severe cases or for individuals at higher risk of complications. Calamine lotion and oatmeal baths can help relieve itching.
Shingles: Antiviral medications (e.g., acyclovir, valacyclovir, famciclovir) are used to reduce the severity and duration of the outbreak. Pain relievers (e.g., over-the-counter pain relievers, prescription pain medications) are used to manage pain. In some cases, corticosteroids may be prescribed to reduce inflammation. A shingles vaccine is also available to prevent shingles.
Is Communicable
Chickenpox: Highly communicable. Spreads easily through the air by coughing or sneezing, or by direct contact with the blisters.
Shingles: Less communicable than chickenpox. A person with shingles can only spread the virus to someone who has never had chickenpox or the chickenpox vaccine. In this case, the person exposed would develop chickenpox, not shingles. The virus spreads through direct contact with the blisters of the shingles rash.
Precautions
Chickenpox: Isolation of infected individuals, avoiding contact with susceptible individuals (especially pregnant women, newborns, and immunocompromised individuals), good hand hygiene. Vaccination is the best way to prevent chickenpox.
Shingles: Covering the rash, avoiding contact with susceptible individuals (especially pregnant women, newborns, and immunocompromised individuals) until the blisters have crusted over, good hand hygiene. Shingles vaccination for older adults is recommended.
How long does an outbreak last?
Chickenpox: The rash typically lasts for 5-10 days.
Shingles: The outbreak typically lasts for 2-4 weeks. Pain may persist for months or even years after the rash has healed (postherpetic neuralgia).
How is it diagnosed?
Chickenpox: Usually diagnosed based on the characteristic rash.
Shingles: Usually diagnosed based on the characteristic rash and pain pattern. In some cases, a viral culture or PCR test may be performed to confirm the diagnosis.
Timeline of Symptoms
Chickenpox:
Incubation period: 10-21 days
Prodromal symptoms (fever, fatigue, headache): 1-2 days before rash
Rash: Starts as small, red spots that develop into blisters, which eventually crust over. New lesions continue to appear for several days.
Shingles:
Prodromal symptoms (pain, burning, tingling): Several days before rash
Rash: Develops as a band of blisters on one side of the body.
Blisters: Rupture and crust over within 7-10 days.
Important Considerations
Chickenpox: Chickenpox during pregnancy can be dangerous for the fetus. Complications can include pneumonia, encephalitis, and bacterial skin infections.
Shingles: The risk of shingles increases with age and weakened immunity. Postherpetic neuralgia (PHN) is a common complication of shingles, causing chronic pain that can be debilitating. Prompt treatment with antiviral medications can reduce the risk of PHN. The shingles vaccine is highly effective in preventing shingles and PHN.