Varicella (Chicken Fox, Cacar Air)

Berhubung sedang banyak pertanyaan dan kasus Cacar air atau yang disebut dengan Varicella, maka saya akan mencoba mengulas berdasar pengalaman klinis, dan ilmu yang saya peroleh dari Prof. saya di Pediatric Division dulu, walau dalam hal ini istilah cacar air (di Indonesia) sendiri masih perlu dideskripsikan dengan jelas agar memang yang dimaksud adalah sesuai dengan diagnosa Varicella.

Varicella

Epidemiology
Peak onset umur 5 - 9 tahun
Outbreak time: November - January
Incidence: di Indo saya belum punya datanya
Varicella Immunity
1. Dewasa: sekitar 90% immune
2. Dewasa without known VZV history: 75% immune

Etiology
Herpes Varicella zoster virus
Human Herpes Virus (Herpesviridae)

Transmission
Direct contact
Respiratory droplet
Transplacental

Symptoms
Viral Prodrome
1. Fever
2. Anorexia
3. Malaise
4. Headache
5. Myalgia
Pruritic rash
1. Mohon lihat signs untuk descripsi lebih jelas
Signs
Generalized Lymphadenopathy
Rash
1. Crops of small, Red Papules
2. Develop into "Dew Drop on a rose petal" Appearance
1. Oval, "teardrop" Vesicles
2. Erythematous base
3. Spread from trunk to face
1. Minimal limb involvement
2. May involve oral or vaginal mucosa

Differential Diagnosis
Herpes Simplex Virus
Herpes Zoster Virus (Shingles)
Impetigo
Coxsackie virus
Papular Urticaria
Scabies
Dermatitis Herpetiformis
Drug rash

Labs
Complete Blood Count (CBC)
1. Slight Leukocytosis
Vesicular fluid exam (Tzanck Smear)
1. Multinucleated giant cells
2. Epithelial cells with Eosinophilic inclusion bodies
3. Virus
IgG Antibody to VZV (ELISA)
1. Immunity testing indicated in pregnancy

Management: Umum
Reduction of Pruritus
1. Calamine Lotion
2. Oatmeal Bath (Aveeno)
3. Atarax at bedtime
Prevention of Superinfection
1. Apply Bacitracin to denuded lesions until scab forms

Management: Virus Suppression
Normal host: Acyclovir
1. Dose: 20 mg/kg/dose up to 800 mg/dose 5x/day or q4h
2. Efficacy
1. Shortens time of viral shedding
2. Most effective if started within 24 hours of rash
1. Faster cessation of new lesions
2. Fever duration reduced
3. More rapid healing
3. Indications
1. Consider especially in large household
4. Adverse effects
1. Avoid if dehydration present
2. Not associated with short-term viral resistance
5. References
1. Balfour (2001) Pediatr Infect Dis J 20:219
Immunocompromised or pregnancy exposure <20 weeks
1. VZIG within 96 hours of exposure
1. Dose: 5 vials Varicella Zoster Immunoglobulin
2. Acyclovir
1. Initiate as soon as possible with onset of rash
2. Indicated within 10 days of rash onset
3. Dose: 500 mg/m2/day IV divided q8 hours for 7 days

Prevention
Varicella Vaccine (Varivax)
Course
Incubation period: 11-21 days
Infectious
1. Start: 1-3 days before rash
2. End: Final lesion crusted

Complications
Lung involvement (14-30% of adults)
1. Pneumonia Incidence 1 case per 400 adult cases
Encephalitis
Secondary bacterial infection (superinfection) common
1. Cellulitis
2. Abscess
3. Erysipelas
4. Invasive Group A Beta-hemolytic Streptococcus
1. Incidence: 5.2 cases per 100,000 VZV cases
2. Increasing Incidence
3. Suspect if fever persists >3-4 days after exanthem
5. Septic Arthritis
6. Osteomyelitis
7. Staphylococcal pyomyositis
8. Disseminated disease in immunocompromised
Reye's Syndrome
1. Avoid concurrent Aspirin use
Nephritis
Varicella mortality (1987-1992)
1. United States: 80-100 per year (mostly children)
2. Death occurs once every 4 days in United States
3. Most deaths occur under age 20 years old
4. Death often in otherwise healthy children

Complications: Congenital Syndrome (Pregnancy related)
General
1. Non-immune Mother exposed to Varicella Zoster Virus
2. Congenital syndrome risk prior to 20 weeks gestation
3. Not associated with Pregnancy loss
4. Not associated with Preterm Labor
Infant Findings
1. Skin lesions
2. Short limbs and digits
3. Ocular abnormalities
4. Muscular atrophy
5. Intrauterine Growth Retardation
References
Doctor (1995) Pediatrics 96:428