Chickenpox in Adults: Symptoms, Course, and Complications

Chickenpox in adults is no minor childhood ailment: after age 18, the disease is often more severe and leads to complications. Below is what is known about the signs, course, and risks.

What chickenpox is and why adults get it

Varicella is an acute, highly contagious viral disease transmitted by airborne droplets. The causative agent is the varicella-zoster virus, also known as human herpesvirus type 3. Contagiousness reaches 100%: everyone who has not previously encountered the virus becomes ill; susceptibility is estimated at 70%. People of all ages get sick, but children more often: about half are aged 5–9, and around 10% of cases are people aged 14 and older. Immunity is lasting, and repeat cases are extremely rare; in severe immunodeficiency, reinfection is possible. In 10–20% of those who have had the disease, the virus remains inactive in nerve tissue and can later cause shingles.

First signs of chickenpox in adults

The incubation period is 10 to 21 days, most often 14–16 days. A patient is contagious from the end of the incubation period, 48 hours before the rash appears, and remains contagious until all lesions are covered with a crust. A prodromal period begins 1–2 days before the rash: in children it may not manifest, while in adults it usually causes fever and malaise. Therefore, in an adolescent or adult, the disease often begins not with a rash but with a feeling of "coming down with something."

Symptoms of varicella: rash and fever

The main sign is an itchy spotted rash anywhere on the body, including the oral mucosa and the genital area, where it is painful. The rash goes through three stages: spots, then fluid-filled blisters (very itchy, may rupture), then crusts. New spots appear while others turn into blisters or heal. The color of the lesions depends on skin tone; on brown and black skin they are less visible. Before or after the rash, the following occur:

• high fever;
• pain and general malaise;
• headache;
• fatigue;
• loss of appetite.

The disease usually lasts 5–10 days and resolves within 1–2 weeks.

How chickenpox in adults differs from childhood chickenpox

In children, varicella is more often mild. In people over 18, the course is more severe, and mortality is 25–175 times higher than in children. Adults, adolescents, pregnant women, infants, and people with weakened immunity have more severe disease. Prodromal symptoms in adults are usually pronounced, while in children they may be absent.

Complications and risk groups

Complications include bacterial skin superinfection, pneumonia, bronchitis, middle ear inflammation, hepatitis, nephropathy, and eye lesions up to blindness. Neurological complications occur in 1–7.5% of cases, of which 70.5% are encephalitis and 10.6% are meningitis; mortality in varicella encephalitis is 1–20%. Neonatal varicella (the mother falls ill 5 days before delivery or within 2 days after) results in death of the newborn in 30% of cases. Morbidity and mortality are also higher with weakened immunity.

Which diseases resemble chickenpox and when a doctor is needed

The same virus causes shingles — localized skin eruptions, more often in older adults and in immunodeficiency. Its incidence is 131–215 cases per 100,000 population: 46 in people under 15 and 1,424 in those over 75. Such a patient is contagious to those who have not had chickenpox. The diagnosis is confirmed by serological antibody tests and tests for varicella and shingles. A doctor is needed for adults, adolescents, pregnant women, and people with weakened immunity — their disease is more often severe.

Chickenpox itself is not a reason to call an ambulance; 103/112 — for a life-threatening condition.

This material is for reference: it describes signs and risks but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer