You've Got What? Chickenpox and shingles
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Chickenpox (varicella) is a viral infection caused by the varicella-zoster virus. Shingles (herpes zoster infection) is caused by re-activation of the chicken-pox virus.
Chickenpox and shingles are notifiable conditions1
Chickenpox is spread when an infected person talks, breathes, coughs or sneezes tiny particles containing infectious agents into the air. These are called small particle aerosols. Due to their tiny size, small particle aerosols can travel long distances on air currents and remain suspended in the air for minutes to hours. These small particle aerosols may be breathed in by another person. Chickenpox is also spread by contact with or breathing in blister fluid.
Following infection, the virus will remain dormant (resting) in nerve cells near the spinal cord for the rest of the person’s life. Reactivation of this virus causes shingles (herpes zoster) rather than a second attack of chickenpox.
Direct contact with the blister fluid in shingles can cause chickenpox in a non-immune person. There is no spread through the air from people with shingles, except perhaps in some very severe cases of disseminated (widespread) shingles. Contact with chickenpox or shingles cannot lead to shingles in the exposed person since shingles can only follow the reactivation of a previous chickenpox infection.
Symptoms of chickenpox may include:
Image courtesy Public Health Image Library (PHIL), Department of Health and Human Services, Centers for Disease Control and Prevention (CDC-USA)
Chickenpox and shingles have a typical appearance and are usually diagnosed by clinical presentation. This can be confirmed by a swab test of the rash detecting the varicella-zoster virus. A blood test can detect if someone has protection from chickenpox infection in the past, but the test may not be helpful in determining if there is adequate immunity to varicella-zoster virus following vaccination.
(time between becoming infected and developing symptoms)
For chickenpox, 10 to 21 days, commonly 14 to 16 days, but may vary in people whose immune system is suppressed.
(time during which an infected person can infect others)
For chickenpox, from 2 days before the rash appears until at least 5 days after the rash first appears and all blisters have crusted over.
For shingles, a person is infectious from when the rash appears until all blisters have dried up.
Specific antiviral treatment for both chickenpox and shingles is available. Treatment is usually only given to those with severe disease or at risk of severe disease. To be effective, treatment must be commenced early, usually within 24 hours of onset of the rash.
For all cases, calamine lotion or promethazine [Phenergan] (available from pharmacies) may be useful for the itch. If treatment to reduce temperature or discomfort is necessary, paracetamol is recommended. Aspirin should not be given to children or adolescents who have chickenpox or shingles.
Seek medical advice if there are any of the following:
1 - In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.
Image - Chickenpox (varicella) lesions. Image courtesy of Public Health Image Library (PHIL), Department of Health and Human Services, Centers for Disease Control and Prevention (CDC-USA)