A highly contagious viral infection which causes an itchy, blister-like rash on the skin. Chickenpox is highly contagious to those who haven't had the disease or been vaccinated against it. The most characteristic symptom is an itchy, blister-like rash on the skin. Chickenpox can be prevented by a vaccine. Treatment usually involves relieving symptoms, although high-risk groups may receive antiviral medication.A reactivation of the chickenpox virus in the body, causing a painful rash. Anyone who's had chickenpox may develop shingles. It isn't known what reactivates the virus. Shingles causes a painful rash that may appear as a stripe of blisters on the torso. Pain can persist even after the rash is gone (this is called post-herpetic neuralgia). Treatments include pain relief and antiviral medication such as aciclovir or valaciclovir. A chickenpox vaccine in childhood or a shingles vaccine as an adult can minimise the risk of developing shingles.

1. CHICKENPOX

2. • Caused by primary infection with varicella zoster virus (HHV-3) Double stranded DNA
virus belongs to herpesvirus family.Following primary infection virus remains latent later
gets reactivated and results in herpes zoster
• Mode of transmission : droplet infection from the respiratory tract /direct cutaneous
contact with vesicle fluid from skin lesions
• Incubation period : 14-28 days, disease is contagious from 2 days before appearance of
rash till pustules disappear
ETIOLOGY

3. CLINICAL FEATURES
• Rash 1st appears on the trunk then face and finally the limbs
• Lesions first appear as macules papules vesicles pustules dry scabs
• Low grade fever
• In Immunocompromised patients – lesions are haemorrhagic and are numerous ,
dissemination to other organs is quite frequent.

5. Complications
• Bacterial infection of the lesions
• Myocarditis
• Corneal lesions
• Bleeding diathesis
• Perinatal varicella
• Meningitis , encephalitis
• Cerebellar ataxia

6. Diagnosis
• Mainly clinical diagnosis
• Tzanck smear of vesicular fluid shows multinucleated faint cells and epithelial
cells with eosinophilic intranuclear inclusion bodies
• Isolation and culture
• Direct immunofluorescence test
• PCR

7. Treatment
• Symptomatic treatment – Antihistamines and local calamine lotion
• <12 years of age, acyclovir (20 mg/kg PO q6h) is recommended
• For adolescents and adults, acyclovir (800 mg PO five times daily), valacyclovir (1
g PO tid), or famciclovir (250 mg PO tid) for 5–7days is recommended.
• Secondary bacterial infection is treated with local antiseptics or systemic
antibiotics like Cloxacillin

8. Prophylaxis
• Chicken pox vaccine (LA vaccine)
• C/I in pregnancy and immunocompromised patients

9. HERPES ZOSTER

10. Etiology
• Herpes zoster (shingles) is caused due to reactivation of the varicella zoster
virus lying dormant in the dorsal root ganglion following chicken pox in early
life.
Image courtesy -By Renee Gordon

11. Clinical features
• Symptoms and signs are dermatomal in distribution
• T3-L3 most commonly involved
• Pain in the involved dermatome, severe burning in nature persists as long as
vesicles remain.
• Red vesicles appear which dry up in a week’s time leaving scars .
• It can involve cranial nerves also occasionally
• Over the face it may involves the 1st divison of the 5th nerve and 7th nerve
(Ramsay hunt syndrome)
• Individuals presenting with only prodromal symptoms without any rash- “zoster
sine herpete”

12. Spread along the dermatome

13. Complications
• Zoster ophthalmicus (which can lead to blindness)
• Ramsay Hunt syndrome (characterized by pain and vesicles in the external
auditory canal, loss of taste in the anterior two-thirds of the tongue, and
ipsilateral facial palsy),
• Postherpetic neuralgia (pain persisting for months after resolution of cutaneous
disease).
• Immunocompromised pts—particularly those with Hodgkin’s disease and non-
Hodgkin’s lymphoma—are at greatest risk for severe zoster and progressive
disease. Cutaneous dissemination occurs in 40% of these pts and increases the
risk for other complications (pneumonitis, meningoencephalitis, hepatitis).
• Peripheral nerve palsies
• Myelitis

14. Diagnosis
• Mainly clinical
• Tzanck smear of the vesicular fluid
• PCR most sensitive and specific diagnostic test

15. Treatment
• Idoxuridine 5% lotion over the skin , 0.1% sol. For corneal instillation
• Oral acyclovir 800mg 5x/daily / famiciclovir 500 mg 3x/daily /valaciclovir 1gm
3x/daily
• Analgesics
• Calamine lotion
• Corticosteroids along with antiviral drugs in c/o Ramsay hunt syndrome and oral
complications
• Posterherpitic neuralgia- may respond to
carbamazepine/amitriptyline/gabapentine