Chickenpox
Everything you need to know about Chickenpox - symptoms, causes, treatment options available in Australia, and when to see a doctor. Evidence-based medical information.
Overview
Chickenpox, also known as varicella, is a highly contagious viral infection caused by the varicella-zoster virus (VZV). It primarily affects children, although adults can also contract the disease, particularly if they have not been vaccinated or previously infected. The pathophysiology of chickenpox involves the virus entering the body through the respiratory tract, followed by a period of viral replication in the lymph nodes. This leads to a viraemic phase, where the virus spreads throughout the body, culminating in the characteristic vesicular rash [1].
In Australia, chickenpox remains endemic, with the majority of cases being mild. The disease is primarily seen in children under 15 years of age, accounting for over 90% of cases [2]. Despite its prevalence, the introduction of the varicella vaccine has significantly reduced the incidence and severity of chickenpox in Australia.
Statistics and Prevalence in Australia
In 2024, there were 2,359 laboratory-confirmed cases of chickenpox reported in Australia, with 328 associated hospitalisations [3]. The disease remains largely mild, with a high vaccination coverage of 93% among 2-year-olds in 2023 [2]. Mortality rates linked to chickenpox are extremely low, with less than one death per million population per year among those aged 15 and older, and no deaths reported in children under 15 since 1999 [3].
Symptoms and Clinical Presentation
Chickenpox typically presents with a prodrome of fever, malaise, and anorexia, followed by the appearance of a generalised vesicular rash. The rash progresses from macules to papules to vesicular lesions before crusting over. It usually begins on the face and trunk before spreading to the extremities. In some cases, the rash may also involve mucous membranes [4].
Red flag symptoms that require immediate medical attention include difficulty breathing, severe headache, persistent vomiting, or signs of secondary bacterial infection such as cellulitis. Atypical presentations may occur in immunocompromised individuals, pregnant women, and neonates, necessitating a high index of suspicion for early diagnosis and management [4].
Causes and Risk Factors
Chickenpox is caused by the varicella-zoster virus, a member of the herpesvirus family. Transmission occurs via respiratory droplets or direct contact with vesicular fluid from skin lesions. Risk factors for contracting chickenpox include lack of vaccination, close contact with an infected individual, and immunocompromised states [5].
The virus can remain dormant in the body and reactivate later in life, causing herpes zoster (shingles). This reactivation is more common in older adults and those with weakened immune systems [5].
Diagnosis
Diagnosis of chickenpox is primarily clinical, based on the characteristic rash and associated symptoms. In atypical cases or vulnerable populations, laboratory confirmation via polymerase chain reaction (PCR) testing or serology may be warranted [6]. Chickenpox is a notifiable condition in Australia, requiring medical practitioners and pathology services to report cases within five days of diagnosis [6].
Treatment Options in Australia
Management of chickenpox is largely supportive, focusing on symptom relief. Antipyretics such as paracetamol can be used to manage fever, while antihistamines may alleviate pruritus. In severe cases or for individuals at high risk of complications, antiviral therapy with aciclovir may be indicated [7].
The Australian healthcare system provides access to these treatments through the Pharmaceutical Benefits Scheme (PBS), ensuring affordability for patients. Vaccination remains the most effective preventive measure, with the varicella vaccine included in the National Immunisation Program Schedule [7].
Living with Chickenpox
For those diagnosed with chickenpox, maintaining hydration, rest, and skin care are essential components of management. Patients should be advised to avoid scratching lesions to prevent secondary bacterial infections and scarring. Regular follow-up with healthcare providers is recommended to monitor for potential complications [8].
Patient education is crucial in managing chickenpox, with emphasis on recognising red flag symptoms and understanding the importance of isolation to prevent transmission. Psychosocial support may be beneficial for patients and families dealing with the stress of illness [8].
Prevention
Prevention of chickenpox is primarily achieved through vaccination. The varicella vaccine is highly effective in preventing infection and reducing the severity of disease in breakthrough cases. Public health campaigns and school-based vaccination programs have contributed to high vaccination coverage in Australia [9].
In addition to vaccination, infection control measures such as good hand hygiene and respiratory etiquette can help reduce the spread of the virus. Individuals with chickenpox should remain isolated until all lesions have crusted over to prevent transmission to susceptible individuals [9].
Related Articles
You might also be interested in:
- Influenza - Understanding flu symptoms, prevention, and treatment
- COVID-19 - Complete guide to coronavirus symptoms and management
- Fever - Understanding fever causes and when to seek treatment
- Chickenpox - Managing chickenpox symptoms and prevention