(GP)

Overview

• Varicella (chickenpox) is caused by the human alpha herpes virus, varicella zoster
• Varicella-Zoster Virus (VZV) → exclusively human virus, incubation period is around 14 days. After primary infection, can become latent in dorsal root ganglia and trigeminal ganglia.
• Over 80% of people have been infected by the age of 10 years
• In around one third of cases, VZV may re-activate later in life to produce shingles. Risk Factors → HIV or immunocompromise (eg. steroid use, chemotherapy)
• Occurs when a susceptible person is exposed to VZV either by direct contact with lesions or through airborne spread from respiratory droplets
• Risk Factors → exposure to VZV, age 1-9 years, unimmunised status, occupational exposure
• Adults, pregnant women, immunosuppressed patients, and neonates are at high risk of complications from varicella

Making Diagnosis

Clinical Features:

• Fever
• Vesicular Rash → first appears centrally, before spreading to extremities
• Vesicles on Mucous Membranes → in nasopharynx
• Pruritus
• Headache, Fatigue/Malaise, Sore Throat