chicken pox

Chickenpox (VARICELLA)Dr. BOUNIKA ESVANTH RAO,Dr. JERUBA JAYAKUMAR,Dr. NEELAVENI MARIMUTHU SAMY,Dr. PRIYADHARSHINI JOTHI MURUGAN.

ETIOLOGIC AGENT Caused by varicella zoster virus related to

Herpes simplex virusCytomagalo virusEpstein bar virus (EBV)

Primary infection results in Varicella. Recurrent infection results in herpes zoster

(shingles). Source :

&

INCUBATION PERIOD 10- 21 days.

SPREAD OF DISEASE

&

INFECTIOUS PERIOD One two days before the appearance of the

rash and lasts till all the lesions have crusted (5-7 days).

CLINICAL PICTURE

Stage of invasion / prodromal stage. Stage of eruption. Convalescence

STAGE OF INVATION (2-3 days)

Symptoms

Before the appearance of the skin rash enantham develops

STAGES OF ERUPTION

Progress of lesion

Macular Papular Vesicular

Pustular

CONVALECENCE •Rashes lasts for 3-4 days.

•Formation of scabs.

•Superficial scars.

Complete clearance of skin may take few days.

VARITIES OF CHECKEN POX Varicella bulla: characterized by

formation of bullous eruptions.

Varicella ganrenosa: It is seen in ill-nourished children and there are dark crusts are formed in the eruptions which on separation leave behind ulcers.

Varicella haemorrhagica: Uncommon virulent form of varecella . Hemorrhages occur into the vesicles and bleeding may take place from the mucous membrane.

COMPLICATIONS

RESPIRATORY: Laryngitis, Bronchitis, Bronchopneumonia.

SKIN: Erysipelas, Cellulitis, Impetigo.

RENAL: Nephritis .

SYSTEMIC: Arthritis, Myocarditis, Purpura,

Encephalomylitis.

SEVERE IN

DIAGNOSIS

Classical appearance of rash. Aspiration of vesicular fluid. PCR tissue culture. Serological examination for rising titers of

antibodies is only useful in primary infection.

Staining of scrapings in with fluorescein labeled monoclonal antibody.

TREATMENTUse of antivirals Indications:For those patients for whom VZIG is not indicatedDose:Oral acyclovir40mg/kg/day in 4 divided dosesgiven from days 7 to 14 after exposure(Kumagai et al, 1999)

PROPHYLAXIS

Dosage and Timing of VZIG(to be given within 10 days of exposure).0 – 5 Years 250mg by6 – 10 Years 500mg slow11 – 14 Years 750mg intramuscular15 years and older 1000mg injection

PASSIVE IMMUNISATION

LIVE ATTENUATED VARICELLA VACCINE (VARIVAX) In a dose of 0.5 ml is administered in all children above the age of 21 months for immunization.A booster dose after 6 years of vaccination is given in some children.

PROGNOSIS

A case of chicken pox has a self limiting course and in an uncomplicated case prognosis is good.

ANY QUESTIONS?