Varicella-zoster virus (VZV) causes two distinct clinical syndromes: varicella (chickenpox) and herpes zoster (shingles). Chickenpox is highly contagious, with an attack rate of at least 90% among susceptible (seronegative) individuals. Persons of both sexes and all races are infected equally.
The virus is endemic in the population at large; however, it becomes epidemic among susceptible individuals during seasonal peaks—namely, late winter and early spring in the temperate zone.
Incubation period 4to 21 days .
Chickenpox infection is caused by varicella virus. It can spread through direct contact with the rash. It can also spread when a person with the chickenpox coughs or sneezes and you inhale the air droplets. Secondary attack rates in susceptible siblings within a household are 70–90%. Patients are infectious before the onset of the vesicular rash, during the period of vesicle formation (which generally lasts 4–5 days), and until all vesicles are crusted.
- Fever (100°–103°F)
- Loss of appetite
- Sore throat
- The skin lesions—the hallmark of the infection—include maculopapules, vesicles, and scabs in various stages of evolution
- These lesions, which evolve from maculopapules to vesicles over hours to days, appear on the trunk and face and rapidly spread to involve other areas of the body.
- Some individuals have very few lesions, while others have as many as 2000. Younger children tend to have fewer vesicles than older individuals.
- Immunocompromised patients—both children and adults, particularly those with leukemia—have lesions (often with a hemorrhagic base) that are more numerous and take longer to heal.
- Pregnant women
- Immunocompromised patients
- Over crowding
- Steroid drug
- Secondary bacterial superinfection of the skin
- Acute cerebellar ataxia
- Aseptic meningitis
- Transverse myelitis
- Guillain-Barré syndrome
- Corneal lesions
- Bleeding diatheses
- Acute glomerulonephritis
- Perinatal varicella. Illness in this setting is unusually severe because the newborn does not receive protective transplacental antibodies and has an immature immune system. Congenital varicella, with clinical manifestations of limb hypoplasia, cicatricial skin lesions, and microcephaly at birth.
- Wash your hands often with soap and water, or use an alcohol-based hand sanitizer.
- Cover your mouth and nose with your elbow or tissue when you cough or sneeze.
- Avoid touching your eyes, nose and mouth if your hands aren’t clean.
- Avoid close contact with anyone who is sick.
- Avoid large events and mass gatherings.
- Avoid sharing dishes, glasses, bedding and other household items if you’re sick.
- Clean and disinfect surfaces you often touch on a daily basis.
- Stay home from work, school and public areas if you’re sick, unless you’re going to get medical care. Avoid taking public transportation if you’re sick
Diagnosis based on clinical findings
Detection of VZV DNA by PCR include lesions, blood, and saliva.