Chickenpox (varicella) is one of the most common and most infectious diseases in children. The disease
is caused by the primary infection of Varicella zoster virus (VZV), reactivation of latent form of the virus
is manifested as herpes zoster. This paper presents the characteristics of the virus, varicella’s clinical picture, diagnostic capabilities, and also highlights the consequences of intrauterine infection. Although the disease usually presents typically and treatment is usually symptomatic, in some patients, even previously healthy, there can be severe, life‑threatening complications. Newborns, immunocompromised patients, patients during immunosuppression therapy, with haematological disorders and malignancies, and pregnant women are the most vulnerable to severe disease’s course group of patients. In view of the real risk of complications in each patient, deliberate exposure of children to infection by their parents during the so‑called “pox parties” seems extremely irresponsible. Acyclovir is available on the market for over 20 years and is designated for the treatment of infections caused by the Varicella zoster and Herpes simplex virus. In patients with properly functioning immune system VZV infection is mild and requires usually supportive treatment. Most cases of chickenpox do not require antiviral treatment but there are proven benefits from usage of such therapy. According to available studies the use of acyclovir within the first 24 hours after the onset of rash is shortening the appearance of skin eruptions, accelerates their healing and reduces their total number. Acyclovir reduces the duration of fever and mitigates symptoms of the disease. It should be noted that such treatment does not impair long‑term resistance of immune system against VZV. The prevention is available in form of two‑doses varicella vaccination acceptable to start from 9th month of life. Specific immunoglobulin (VZIG) can be applied in selected cases discussed below.