All About Chicken Pox (Varicella)

Chicken pox is an acute viral disease caused by the virus from herpes virus family, is

characterized by the moderate fever, appearance on a skin, mucus membranes small vesicles

with transparent content.

Etiology: DNA containing Varicella-Zoster virus.

Epidemiology:

• Source of infection – ill person with chicken pox, (rare – herpes zoster).

• Chickenpoxis is transmitted from person to person by respiratory route or by the direct contact.

• Susceptible organism – everyone, who didn’t ill before.

• Infection confers lifetime immunity – in 3 % of patients it may develop for the 2nd

time.

Pathogenesis:

1.     Inoculation of virus and it’s replication in epithelial cells of upper respiratory tract.

2.     With lymph it enters to the blood and viremia develops.

3.     Damage of the skin epithelium and mucosa epithelium.

4.     Damage of the nervous system – (intravertebral ganglia, brain and cerebellum cortex, subcortical region).

5.     Generalization of the infection (damage of liver, kidneys, lungs) in immunosupressed people.

Clinical presentation

• The incubation period ranges from 11 to 21 days (most cases 14-17 days).

• The contagious period extends from 1 to 2 days before the rashes erupt until all of the lesions have crusted (5 days after the last rashes have appeared).

• The prodrome consists of 1 to 2 days of fever, headache, malaise, and anorexia.

• The rashes, often pruritic, begin as a maculae and progresses rapidly through the stages of papule, vesicle (photo 12), and crusted lesion (photo 13). The spots first appear on the face or trunk, obvious on the scalp (photo 14) and, at the height of the illness, are more numerous centrally than distally (photo 15). In severe cases may be present on palms and soles (as spots and papules) (photo 16). The lesions erupt in crops for 3 to 4 days (sometimes to 7 days) and it is characteristic of the rashes that lesions in different stages of development may be found on one area (false polymorphism) (photo 17). The vesicle is a 2 to 3 mm oval filled with clear fluid surrounded by an erythematous base. The fluid clouds and a crust forms appear within 1 day. Lesions occurring on the mucous membranes do not crust but form a shallow ulcer (photo 18, 19). Posterior cervical lymph nodes usually are enlarged (photo 20).

 

stages of papule, vesicle

crusted lesion

crusted lesion on the scalp

Lesions are more numerous centrally than distally

spots and papules on soles

Rashes polymorphism

Rashes on the oral mucosa

Posterior neck lymphadenitis

The congenital varicella syndrome in case of infection in the 1st trimester of pregnancy by VZ-virus – may occur embryopathies. Maternal varicella 5-10 days before delivery result in mild chickenpox in newborn from the first days of his life. Maternal varicella 4 days or less before delivery may result in severe disseminated or total chickenpox in the newborn.

Clinical classification

Type

• Typical forms

• Atypical forms:

- Effaced (rudimentary): in children with passive immunity received transplacentally,

or due to immune globulin or plasma injection in the latent period (not numerous rashes as papules with several vesicles appear, body temperature is normal).

- Bullous: together with typical rashes appear large vesicles up to 2-3 cm with cloudy content, after them erosion and pigmentation develop.

- Hemorrhagic: develops in immune compromised children, vesicles content become hemorrhagic, crusts are black. Other signs of hemorrhagic syndrome are present (petechia, ecchymoses, nasal bleeding, hemorrhages into the inner organs).

- Gangrenous: develops in immune compromised children in case of bad care. Vesicles content become hemorrhagic with infiltration around them, crusts are black,ulceration is typical.

- Generalized (visceral) is typical for the newborns and in case of the immune deficit.

Severity	Severity criterions	Duration
Mild	vesicles rashes are not numerous on the skin,  body t° 37,5-38 °С	1.  Smooth, without complications 2.  Complicated by encephalitis, neuritis, polyradiculoneuritis ·        Complicated by secondary bacterial infection as lymphadenitis, pyodermia (staphylo-and streptodermia), erysipelas, phlegmon, abscess, sepsis.
Moderate	Considerable presence of the vesicles rashes on a skin, single on mucus membranes of the oral cavity, body t° 38-39 °С
Severe	numerous rashes, hardening on the stage of vesicles on a skin and mucus membranes, body t° is up to 40 °С and higher
Generalized  (visceral)	neurotoxicosis with a convulsive syndrome and meningoencephalitic reactions, hyperthermia, multiple rashes as vesicles quite often with the hemorrhagic impregnation, damage of the internal organs
Effaced  (rudimentary)	rashes on the skin does not achieve the stage of vesicles (only macula-papules), body t° is normal

Complications:

- Secondary bacterial – infection of lesions (with staphylococci as pustulosis (photo 21) or b-hemolytic group A streptococci as erysipelas, phlegmona (photo 22) are the most common complications; also may be otitis, pneumonia, lymphadenitis, stomatitis, purulent conjunctivitis and keratitis, sepsis, osteomyelitis.

Pustulosis

Phlegmona

- Viral: Primary varicella pneumonia affects immunocompromised patients and up to 35 % of normal adults; croup; Encephalitis follows varicella in fewer than 1:1000 cases (involvement of the cerebellum, or cerebrum), meningoencephalitis, encephalomyelitis, less common – Guillain-Barre syndrome, transverse myelitis, optic neuritis, and facial nerve palsy.

- Rare complications: idiopathic thrombocytopenic purpura, nephritis, myocarditis, arthritis, acute adrenal insufficiency because of adrenal hemorrhages.

Work-up. Laboratory tests are rarely needed. In CBC: leucopenia, relative lymphocytosis, normal ESR. Vesicle scrapings contain multinucleated giant cells, and vesicle fluid contains virus in the first days of illness. It could be detected by the:

• Immune Fluorescent method;

• Serological reactions: CBR, Immune-enzyme reaction, IHAR to find antibodies

against viruses with fourfold increasing of antibodies title in 10-14 days may be

used;

• CSF investigation (signs of serous meningitis) – in case of meningoencephalitis;

• Virological separation of the VZ-virus on embryonic cells.

Diagnosis example: Chickenpox, typical form, moderate severity, complicated by

the bilateral medial otitis.

Differential diagnosis should be performed among early impetigo, insect bites, scabies,

and urticarial lesions.

Features of chicken pox in infants

·Beginning from a general infectious signs (malaise, anxiety, absence of appetite), dyspepsia phenomena.

·Body t° is normal or subfebrile, grows when rashes appear.

·Rashes appear on 2nd-5th day, massive, sometimes remain in one phase of development (gradual development of illness).

·Neurotoxicosis (cramps, meningeal symptoms).

· Possible visceral signs.

· Frequent is secondary bacterial infection.

Evidences for obligatory hospitalization of patients with infectious exanthema

·       The severe form of disease, when appears need in undertaking of intensive therapy; patients with moderate forms at age before 3 years.

7.     Sick children from families with bad social-home conditions, especially in the event of impossibility of their isolation to prevent infections transmission.

8.     Absence of conditions for examination and treatment at home.

9.     Sick children from closed children institutions.

Advantages of the home treatment

1. Possibility of additional infection by hospital bacteria is completely excluded.

2. Realization of individual care principle for sick child is more full.

3. Avoiding stressful reactions, which could appear in case of hospital treatment.

Treatment in home conditions is possible

1. In conditions of isolated flat.

2. In case of satisfactory material position of the parents.

3. In case of parents desire to organize individual care and treatment at home.

Treatment

In most cases only symptomatic (Basic therapy) up to disappear of clinical signs

• Antiseptic fluids for skin lesions to prevent secondary bacterial infection (1 % brilliant green, 1-2 % KMnO4);

• Gurgling with oral antiseptic fluids after the food intake;

• Antihistamines for itching;

• Acetaminophen for fever control.

Etiological therapy by Acyclovir (IV 10 mg/kg 3 t.d. for 7 days or up to 48 hours the last elements appear) – for immunocompromised children:

n Patients with oncohematologic diseases;

n Patients after bone marrow or inner organs transplantation;

n Patients who achieve corticosteroids;

n Patients with the primary immune deficit;

n Patients with HIV-infection;

n Inborn Chicken pox;

n Chicken pox complicated by the damage of CNS, hepatitis, thrombocytopenia, pneumonia;

n  And Severe forms of Chicken pox (Acyclovir orally 80 mg/kg/day 4 t.d. for children elder than 2 years and teenagers).

Also for severe cases in neonates – Varicella-Zoster immune globulin (0.2 ml/kg).

In case of encephalitis:

Base therapy:

• Bed regimen till body temperature normalization, disappearance of general cerebral and considerable improvement of focal neurological signs, not less than 14-16 days;

• A diet (before stable vital functions is due to adequate parenteral infusion therapy);

• Brest feeding or bottle feeding by adopted formulas for infants, in the first day 1/2-1/3 of average volume with a next increase to the complete volume during 2-3th days;

• A milk vegetable diet (№5) is appointed for preschoolers or school children, 5-6 times per day with the next passing to the diet №2 whether №15 (depending the age) in the recovery period;

• Oral fluids intake corresponds to age norms (with including the IV fluids);

• Antibacterial therapy: for infants at presence of concomitant bacterial infection, chronic infection, inflammatory changes in the CBC (by the broadspectrum antibiotic in average therapeutic doses, a short course).

Etiologic therapy:

• In encephalitis without the expressed general cerebral symptoms – IV acyclovir 10 mg/kg 3 times per day during 7-10 days; in the case of encephalitis with the expressed general cerebral symptoms (violation of consciousness, cramps) –15-30 mg/kg 3 times per day during 10-14 days, then continue 200-400 mg 5 times per day PO during 14 days;

• In meningitis IV acyclovir 10-15 mg/kg 3 times per day during 5-7 days.

Pathogenetic therapy:

• Glucocrticoids 3-5 mg/kg (by prednisolon), course not more than 10 days;

• vascular medicine (penthoxyphyllin, nicergolin and others like that);

• In posthypoxia period – nootrops, vitamins group B.

• In case of CSF hypertension – dehydration by 25 % MgSO4 IM, lasix 1-3 mg/kg IV or IM, acethazolamid orally.

• In case of seizures – Anticonvulsant therapy: benzodiasepins (seduxenum, sibasonum)

0.3-0.5 mg/kg IV, if they are ineffective – 1 % hexenalum or thiopenthalum sodii

in 3-5 mg/kg IV. Dehydration therapy: lasix 2-3 mg/kg IM or IV.

Prevention:

1. To isolate ill person until the 5 day after the last vesicles has appeared.

2. To isolate contacts from 11 till 21 day after exposure.

3. VZ immune globulin in immunocompromised children (not later than 72 hours

after exposure).

Key words and phrases: Varicella-Zoster, chickenpox, polymorphism, congenital

varicella syndrome, bullous varicella, multinuclear giant cells, acyclovir, Varicella-Zoster

immune globulin, immunocompromised children.