Chicken pox

21 Jul

Chickenpox is an infection caused by the varicella-zoster virus usually occuring in childhood ages. However, it can affect adults which holds the risk of more severe symptoms such as neurological complications (herpes zoster). The infection can impact any part of the body.

- Studies found that more than 90% of cases occurs in children younger than 10 years
- Since the introduction of the varicella vaccine, the incidence of the condition has reduced up to 90%
- Tropical and semi-tropical climates in countries have a higher risk of incidence of adult chickenpox than temperate climates eg. UK. [1]
- According to a study found in Vaccine, almost all children will experience chickenpox during the first 5 years of life [2]
- Children usually likely to have chickenpox in winter and spring [3]
- Usually from the airborne respiratory droplets from an infected host who carried the varicella zoster virus [4]
Medical Students
- Initial Infection:
  - Virus enters via the conjunctivae or upper respiratory mucosa
  - Primary replication occurs in regional lymph nodes (2–4 days post-infection)
  - Viremia (virus in bloodstream) develops 4–6 days after infection
- Secondary Viral Replication:
  - Occurs in organs, especially the spleen and liver
  - Virus then invades capillary endothelial cells and the epidermis
- Skin Involvement:
  - Virus infects the malpighian layer of the skin (site of active cell division)
  - Leads to intra- and intercellular oedema
  - Results in the formation of vesicular skin lesions
- Immune Response:
  - Infection triggers production of IgA, IgG, and IgM antibodies
  - These antibodies provide lifelong immunity
- Latency and Reactivation:
  - In secondary infections (e.g., herpes zoster), the virus travels from the skin/mucosa to local sensory nerves
  - Virus becomes latent in dorsal root ganglia
  - Reactivation of the latent virus causes herpes zoster (shingles)
  - Can result in neurological symptoms, especially in immunocompromised or elderly patients
Patients
- How the virus enters the body:
  - The virus enters through the eyes or airways (like the nose, mouth, or throat)
- Early spread in the body:
  - After 2–4 days, the virus spreads to the lymph nodes (small glands that help fight infection)
  - After 4–6 days, the virus enters the bloodstream and spreads through the body
- Involvement of organs and skin:
  - The virus multiplies in important organs like the liver and spleen
  - Then it moves to the blood vessels and the skin, especially to layers where new skin cells are made
- What causes the rash and blisters:
  - The virus causes swelling inside and between skin cells
  - This creates the typical rash and blisters seen in chickenpox
- Immunity:
  - After infection, your body makes proteins (antibodies) that stay for life and help prevent future infections
- If the virus becomes active again (shingles):
  - After chickenpox, the virus can stay "asleep" in the nerves for years
  - Later in life, it can reactivate and cause shingles (herpes zoster), often with a painful skin rash
  - This reactivation can also cause nerve pain or other symptoms, especially in older adults or people with weak immune systems [1]
- Immunocompromised people (no evidence of immunity to varicella virus)
- Newborns with mothers who had varicella 5 days before or 2 day after delivery
- People with HIV or AIDS
- Pregnancy women without immunity to the varicella virus [4]
- Headache
- Fever
- Malaise (sickness)
- Flushing of the skin
- Rash in early stages
- Itchy spots with redness
- Crop (clustered) pattern of spots
- Crusting of the spots
- Severe cases include the trunk, extremities, or face
- Ulcering of the spots (lesions) [5]
- Clinical examination from presentations but may not be conclusive
- History taking including recent exposure to chickenpox, risk factors, typical features of chickenpox and symptoms associated with chickenpox complications.
- Polymerase Chain Reaction testing for the varicella virus; taken from the scabs, fluids from the spot and scrapings [6,7]
- Other viral infections that present with vesicles (spots):
  - Herpes simplex (STD)
  - Herpes zoster (shingles)
  - Coxsakie virus- Hand, foot and mouth disease
- Infections:
  - Impetigo
  - Scabies
  - Syphilis (STD)
  - Meningitis
  - Toxic shock syndrome- medical emergency caused by bacteria
- Skin disorders:
  - Drug eruption
  - Insect bites
  - Erythema multiforme- reaction to allergies
  - Guttate psoriasis- skin disorders presented with small, teardrop spots caused by the streptococcal infection
  - Papular urticaria- reaction to allergies presented with papules (skin lesions) [6]
Prevention
- Chickenpox vaccine is provided if the risk of spreading the virus to people who cannot respond to an infection adequately (immune suppressed)
- Eg. A child can be vaccinated with 1 parent who is undergoing chemotherapy [7]
Medical Student
- In mild cases of chickenpox, advise symptomatic treatment. This includes;
  - A wet compress to reduce itching and fever
  - Anti-histamines to alleviate hay fever and other symptoms)
  - Oatmeal baths for severe itching
  - Keeping the underclothing clean and keep the nails clipped
  - School or work should be not be attended until the final lesions have crusted over.
- Prescribe oral antivirals to healthy people who are at risk of experiencing a moderate-severe disease, drugs include;
  - Valacylovir
  - Famciclovir
  - Acylovir
- Consider prescribing antipyretics (reduces fever) such as;
  - Acetaminophen
Patients
- In mild cases of chickenpox, advise treatment which manages the symptoms of chickenpox (including fever, itching etc). This includes;
  - A wet compress to reduce itching and fever
  - Anti-histamines to alleviate hay fever and other symptoms)
  - Oatmeal baths for severe itching
  - Keeping the underclothing clean and keep the nails clipped
  - School or work should be not be attended until the final lesions have crusted over.
- Drug treatment for the virus are called anti-virals and they include;
  - Valacylovir
  - Famciclovir
  - Acylovir
- Consider prescribing antipyretics (reduces fever) such as;
  - Acetaminophen [7]
- Herpes zoster is the reactivated version of varicella zoster (occurs after a latent/ non expressive period of the varicella zoster)
- Bacterial infections in children
- Viral pneumonia in adults- respiratory infection
- Cerebella ataxia- brain impacted, causing difficulties in co-ordination, balance and speech
- Encephalitis- blain becomes inflammed
- Septicemia- blood infection
- Toxic shock syndrome- medical emergency caused by bacteria
- Necrotizing fasciitis- rare bacterial infection caused by group A streptococcus
- Osteomyelitis- infection of the long bones in the body
- Septic arthritis- infection of the joints
- Bleeding problems (hemorrhagic) [4]
- Chickenpox isn’t serious
- Chickenpox only affects children
- Vaccines are less effective than exposure to chickenpox
- Vaccines cause chickenpox
- Chickenpox can only be achieved through direct contact
- All children should be exposed to the virus as soon as possible
- Vaccine provides 100% protection against chickenpox [8,9]
- How do I know if I had chickenpox as a child? How can I check?
- What protection can be provided for people with immune complications?
- How can I contact for support if I have been in contact with chickenpox and I am pregnant?
- How do I know what chickenpox stage of development I am on?
- How does chickenpox spread?
- What are the side effect of the chickenpox vaccine?
- Why should my child get the vaccine rather than build up natural immunity through exposure? [10,11]
- Chickenpox aware
- American Academy of Dermatology
- Bupa
[1] https://emedicine.medscape.com/article/1131785-overview#a5
[2] https://pubmed.ncbi.nlm.nih.gov/17919788/
[3] https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/chickenpox/
[4] https://www.cdc.gov/chickenpox/about/index.html
[5] https://www.msdmanuals.com/en-gb/professional/infectious-diseases/herpesviruses/chickenpox?query=chicken
[6] https://cks.nice.org.uk/topics/chickenpox/diagnosis/diagnosis/
[7] https://www.health.state.mn.us/diseases/varicella/hcp/labtesting.html#testvar
[8] https://www.whattoexpect.com/first-year/health/chickenpox-myths
[9] cosm.com/skin/chickenpox-myths-facts/
[10] https://www.nhs.uk/conditions/vaccinations/chickenpox-vaccine-questions-answers/
[11] https://www.glitc.org/2020/wp-content/uploads/2020/08/BACIP_Fact-Sheet_Varicella_Final.pdf