Chickenpox

Chickenpox (varicella, Slovak sheep pox) is one of the most common pediatric infectious exanthema diseases. It is caused by the varicella-zoster virus (VZV) familyherpesviruses. It is a highly contagious disease that is transmitted primarily through direct contact. The incubation period is about 2 weeks. It is manifested by itchy vesicular rash and enanthema, which appears in waves, so all stages (macula, papule, vesicle, crust) are present on the body at the same time. It can be severe in immunocompromised individuals. The disease leaves lifelong immunity. When the virus is reactivated, it is formed  shingles. Vaccination against varicella is voluntary.

General characteristics

 * typically aged 1-6 years ;
 * highest incidence: during winter and spring;
 * transmission: droplets or direct contact with lesions;
 * incubation: 14–16 days, more usually 1-3 weeks ;
 * infectivity starts 2 days before the onset of blisters and ends together with the covering of the last blisters with crusts ;
 * occurs after the disease long-term immunity;
 * during primary infection the disease occurs with generalized rash – chickenpox - after healing the virus persists in the cells of the sensitive ganglia of the cerebral and spinal nerves and may reactivate;
 * reactivation of the virus causes shingles.

Epidemiology

 * The reported incidence of varicella in the Czech Republic in the years 2000–2009 is 33,500–52,500 cases per year, ie 330-515 patients per 100 000 population per year.

Clinical picture

 * the rash usually starts at head and torso, from where it spreads throughout the body;
 * development of rash: red macules → papules → vesicles → pustules → crusts ;
 * the simultaneous occurrence of different stages is typical (sowing in several waves for 2-5 days);
 * the rash also appears in forehead, it tends to be more on the torso and in places of skin irritation;
 * also on the mucous membranesof the mouth - it quickly turns into small sores;
 * other symptoms:
 * headache,
 * anorexia,
 * upper respiratory tract infection,
 * fever,
 * itching ,
 * in  adults  often prodromes - fever and greater alterations in general condition, more complications;
 * in  healthy children  it usually takes place without complications''';
 * we will encounter a more difficult course:
 *  in neonates  and  infants of mothers  who did not have varicella;
 * in  malnourished  and  weakened  ( congenital immune defects], malignancies, immunosuppression, etc.):
 * rich distribution of efflorescences on the skin and mucous membranes;
 * lungs or liver involvement;
 * development of hemorrhagic diathesis - this is called  progressive varicella    ''.

Diagnostics

 *  clinically : typical rash, its distribution and development;
 *  serology : VZV IgM;
 *  direct detection of virus :  electron microscopy blister fluid.

Differential diagnostics

 * Streptococcus impetigo,
 * folliculitis,
 * insect stings,
 * enterovirus vesicular rash,
 * disseminated HSV,
 * allergic rashes.

Treatment

 * 1) symptomatic (fever, itching):
 * 2) *  topical  (liquid powder,  antiseptic ointment);
 * 3) *  general  (paracetamol, antihistamine,  ATB in  bacterial superinfection);
 * 4) ** we make sure there is a sufficient "fluid supply";
 * 5) ** we isolate the sick at home;
 * 6) ** we mainly protect children with reduced immunity from infection - we give  specific immunoglobulins to the infectionno later than 72 hours '' after exposure ← this either prevents infection or prolongs the incubation and then alleviates the course;
 * 7) u  immunosuppressed  and in severe acyclovir, possibly immunoglobulin ;
 * 8) * varicella-zoster immunoglobulin is administered prophylactically:
 * 9) **  pregnant women with a negative history of varicella  who have been exposed to the infection;
 * 10) **  neonates of seronegative mothers  who have been exposed to the infection for the first 6 weeks of life;
 * 11) **  premature infants  exposed to infection regardless of maternal history.

Complications

 * efflorescence impetiginization;
 *  hepatitis;
 * pneumonia - mainly in cystic fibrosis, otherwise rare;
 * encephalitis - often affects the cerebellum ;
 * in adults mainly interstitial pneumonia and serous arthritis;
 * Orchitis as a complication of chickenpox is very rare, or there is no association with orchitis after or during VZV infection.

Prevention

 * voluntary vaccination (measles + rubella + mumps + varicella)

Infections in pregnancy

 * infection in the first 5 months of pregnancy:
 * 2% risk of fetal harm;
 * defects of the nervous system, eye, skeleton, scarring of the skin;
 * is not a reason for abortion;
 * infection last 5 days before delivery or 2 after delivery :
 * in the newborn, the course of the varicella may be more severe than in the postnatal infection due to the absence of transmitted maternal antibodies.

Source

 * ws: Plané neštovice