Makindo Medical Notes

Related Subjects: |Herpes Varicella-Zoster (Shingles) Infection |Chickenpox Varicella Infection |Varicella Cerebral Vasculopathy |Herpes Viruses |Herpes Zoster Ophthalmicus (HZO) Shingles

Up to 33% of the general population may be colonized with Staphylococcus aureus (including MRSA) on areas of their body, such as the nose, skin, axilla, and groin.

About

• The varicella-zoster virus (VZV) causes chickenpox (varicella) as the primary infection and shingles (zoster) upon reactivation.
• Chickenpox is a highly contagious, mild disease primarily affecting children under 10 years old, typically with seasonal peaks from January to April.
• While generally self-limiting, adults tend to experience more severe disease than children.
• Shingles occurs only in individuals who have previously had chickenpox; however, exposure to shingles can lead to chickenpox in non-immune individuals.

Transmission

• Chickenpox is highly contagious, with a 90% transmission rate among non-immune individuals exposed to the virus.
• Incubation lasts 10-21 days, with infectiousness highest 1-2 days before rash onset and continuing until all vesicles have crusted over.
• Transmission occurs via airborne respiratory droplets, direct contact with vesicle fluid, or indirect contact (e.g., contaminated clothing or linen).

Clinical Presentation

• Initial cold-like symptoms may include fever, headache, and myalgia. This is followed by an intensely itchy vesicular rash, primarily affecting the trunk with limited involvement of hands and feet.
• Severity varies, and infection may be asymptomatic in some cases. Immunocompromised individuals may have prolonged infectivity.

Complications

• Risk of complications is higher in infants under 1 year and adults over 15. Most children recover fully, but complications can include neurological issues like meningitis or encephalitis, and in some cases, glomerulonephritis or myocarditis.
• Secondary bacterial skin infection, especially in children under 5, can cause high fever and erythema around lesions.
• Adults, particularly smokers, may develop severe lung involvement such as varicella pneumonia.

Varicella in Pregnancy

• Maternal VZV Infection: Increased morbidity with pneumonia in 10-14% (severity rises in later gestation), 1% mortality risk, hepatitis, and encephalitis.
• Fetal Varicella Syndrome (FVS): Occurs between the 3rd and 28th week of gestation, causing potential dermatomal scarring, eye defects, limb hypoplasia, and neurological abnormalities.
• Varicella in Newborns: Severe infection is likely if maternal infection occurs near delivery. Risk is highest if the mother develops a rash 7 days before to 7 days after delivery.

Investigations

• Clinical diagnosis is usually sufficient; however, laboratory confirmation via vesicle fluid microscopy or serology may be used to confirm immunity.

Management

• Isolate the patient and provide symptomatic treatment to reduce fever and itchiness. Antibiotics are ineffective as chickenpox is viral.
• High-risk individuals (e.g., immunocompromised, neonates) may require antiviral prophylaxis or VZIG (Varicella Zoster Immunoglobulin).
• Varicella prevention is crucial for high-risk, seronegative patients who should avoid exposure and seek healthcare promptly if exposed.

Management of Chickenpox in Pregnancy

• Pregnant women with chickenpox symptoms should contact their GP immediately and avoid contact with susceptible individuals.
• Hospital assessment is recommended for pregnant women with respiratory or severe symptoms, especially if they are high-risk (e.g., smokers, chronic lung disease, or immunosuppressed).
• Isolation is advised for hospitalized women to prevent spread.
• Oral Aciclovir (800 mg five times daily for 7 days) is advised for those presenting within 24 hours of rash onset and beyond 20 weeks of gestation. Intravenous Aciclovir is recommended for severe cases.

References

• Chicken Pox (Varicella Zoster Virus) Guideline (GL805)