Definition
An acute and highly contagious disease of viral etiology that is characterized by vesicular eruptions on the skin and mucous membrane with mild constitutional symptoms.
Infectious agent
Herpes virus varicellae – a DNA containing virus
• Man is the only source of infection
• Closely related or identical to herpes zoster virus
Incubation period
• 10 to 21 days; or maybe prolonged after passive immunization against chicken pox.
Mode of transmission
1. Direct contact with patients who sheds the virus from the vesicles
2. Indirect contact, through linens or fomites
3. Airborne, or spread by droplet infection
Period of communicability
The patient is capable of transmitting the disease about a day before the eruption of the first lesion up to about 5 days after the appearance of the last crop.
Clinical Manifestations
1. Pre-eruptive manifestations are mild; fever and malaise.
2. Eruptive stage
• Rash start from the trunk (unexposed area), then spread to other parts of the body
• Initial lesions are distinctively red papules where contents become milky and pus-like within 4 days.
• In adult and bigger children, the lesions are more widespread and more severe.
• There is a rapid progression so that transition is completed in 6-8 hours.
• Vesicular lesion are very pruritic
• All stages are present simultaneously before all are covered with scabs, known as “Celestial map”
• All lesion appear in different stages at one time or it will pass through the following stages: macule, papule, vesicles, pustule, crust
Macule – a lesion that is not elevated above the skin surface
Papule – a lesion that is elevated above the skin surface with a diameter of
about 3mm.
Vesicle – a pop-like eruption filled with fluid; the thin-walled vesicle easily burst
and dry up in 3 – 5 days.
Pustule – a vesicle that is infected or filled with pus. If the lesion becomes
infected the scar may be big and wide.
Crust – a scab or eschar. This is a secondary lesion caused by the secretion of
vesicle drying on the skin.
- The scars are superficial, depigmented and take time to fade out.
Diagnostic Test
1. Determination of V-z virus through Complement Fixation Test.
2. Determination of V-Z virus through Electron Microscopic examination of vesicular fluid.
Complications
1. Secondary infection of the lesions; furuncles, cellulites, skin abscess, erysipelas
2. Meningoencephalitis
3. Pneumonia
4. Sepsis
5. Hemorrhagic Varicella
Treatment modalities
1. Zoverax 500mg/tablet, 1 tab 2x a day for 7 days.
2. Oral acyclovir 800mg 3x a day for 5 days.
3. Oral anti-histamine to symptomatic pruritus
4. Calamine lotion
5. Do not give salicylates
6. Antipyretic for fever