Chickenpox, also known as varicella ( ), is a highly contagious disease caused by varicella zoster virus (VZV), a member of the herpesvirus family. The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It usually starts on the chest, back, and face. It then spreads to the rest of the body. The rash and other symptoms, such as

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

, tiredness, and

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

s, usually last five to seven days. Complications may occasionally include

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

, inflammation of the brain, and bacterial skin infections. The disease is usually more severe in adults than in children. Chickenpox is an

airborne disease Airborne transmission or aerosol transmission is Transmission (medicine), transmission of an infectious disease through small particulates, particles suspended in the air. Infectious diseases capable of airborne transmission include many of c ...

which easily spreads via

human-to-human transmission Human-to-human transmission (HHT) is an epidemiologic vector, especially in case the disease is borne by individuals known as superspreaders. In these cases, the basic reproduction number of the virus, which is the average number of additional ...

, typically through the coughs and sneezes of an infected person. The

incubation period Incubation period (also known as the latent period or latency period) is the time elapsed between exposure to a pathogenic organism, a chemical, or ionizing radiation, radiation, and when symptoms and signs are first apparent. In a typical infect ...

is 10–21 days, after which the characteristic rash appears. It may be spread from one to two days before the rash appears until all lesions have crusted over. It may also spread through contact with the blisters. Those with shingles may spread chickenpox to those who are not immune through contact with the blisters. The disease can usually be diagnosed based on the presenting symptom; however, in unusual cases it may be confirmed by

polymerase chain reaction The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed st ...

(PCR) testing of the blister fluid or scabs. Testing for

antibodies An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...

may be done to determine if a person is immune. People usually only get chickenpox once. Although reinfections by the virus occur, these reinfections usually do not cause any symptoms. Since its introduction in 1995 in the United States, the varicella vaccine has resulted in a decrease in the number of cases and complications from the disease. It protects about 70–90 percent of people from disease with a greater benefit for severe disease. Routine immunization of children is recommended in many countries. Immunization within three days of exposure may improve outcomes in children. Treatment of those infected may include calamine lotion to help with itching, keeping the fingernails short to decrease injury from scratching, and the use of

paracetamol Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol. Parac ...

(acetaminophen) to help with fevers. For those at increased risk of complications, antiviral medication such as aciclovir is recommended. Chickenpox occurs in all parts of the world. In 2013, there were 140 million cases of chickenpox and shingles worldwide. Before routine immunization the number of cases occurring each year was similar to the number of people born. Since immunization the number of infections in the United States has decreased nearly 90%. In 2015 chickenpox resulted in 6,400 deaths globally – down from 8,900 in 1990. Death occurs in about 1 per 60,000 cases. Chickenpox was not separated from

smallpox Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus '' Orthopoxvirus''. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (W ...

until the late 19th century. In 1888 its connection to shingles was determined. The first documented use of the term ''chicken pox'' was in 1658. Various explanations have been suggested for the use of "chicken" in the name, one being the relative mildness of the disease.

Signs and symptoms

The early (

prodromal In medicine, a prodrome is an early Medical sign, sign or symptom (or set of signs and symptoms, referred to as prodromal symptoms) that often indicates the onset of a disease before more diagnostically specific signs and symptoms develop. More spe ...

) symptoms in adolescents and adults are nausea, loss of appetite, aching muscles, and headache. This is followed by the characteristic rash or oral sores,

malaise In medicine, malaise is a feeling of general discomfort, uneasiness or lack of wellbeing and often the first sign of an infection or other disease. It is considered a vague termdescribing the state of simply not feeling well. The word has exist ...

, and a low-grade fever that signals the presence of the disease. Oral manifestations of the disease (enanthem) not uncommonly may precede the external rash (exanthem). In children, the illness is not usually preceded by prodromal symptoms, and the first sign is the rash or the spots in the oral cavity. The rash begins as small red dots on the face, scalp, torso, upper arms, and legs; progressing over 10–12 hours to small bumps, blisters, and pustules; followed by umbilication and the formation of scabs. At the blister stage, intense itching is usually present. Blisters may also occur on the palms, soles, and genital area. Commonly, visible evidence of the disease develops in the oral cavity and tonsil areas in the form of small ulcers which can be painful, itchy, or both; this enanthem (internal rash) can precede the exanthem (external rash) by 1 to 3 days or can be concurrent. These symptoms of chickenpox appear 10 to 21 days after exposure to a contagious person. Adults may have a more widespread rash and longer fever, and they are more likely to experience complications, such as varicella

. Because watery nasal discharge containing live virus usually precedes both exanthem (external rash) and enanthem (oral ulcers) by one to two days, the infected person becomes contagious one to two days before recognition of the disease. Contagiousness persists until all vesicular lesions have become dry crusts (scabs), which usually entails four or five days, by which time nasal shedding of live virus ceases. The condition usually resolves by itself within a week or two. The rash may, however, last for up to one month. Chickenpox is rarely fatal, although it is generally more severe in adult men than in women or children. Non-immune pregnant women and those with a suppressed immune system are at highest risk of serious complications. Arterial ischemic stroke (AIS) associated with chickenpox in the previous year accounts for nearly one-third of childhood AIS. The most common late complication of chickenpox is shingles (herpes zoster), caused by reactivation of the ''varicella zoster'' virus decades after the initial, often childhood, chickenpox infection. File:Chickenpox Adult back.jpg, The back of a 30-year-old male after five days of the rash File:Ploketes d' aiwe dj3 costé.jpg, A 3-year-old girl with a chickenpox rash on her torso File:Bem chickenpox vannkopper 20140318.jpg, Lower leg of a child with chickenpox File:Vicki Pandit - Howrah 2014-04-06 9845.JPG, A child with chickenpox File:A child with chickenpox (01).jpg, A child with chickenpox on her face. File:Windpocken.jpg, A child with chickenpox File:Chickenpox blister-(closeup).jpg, Chickenpox blister closeup, day 7 after start of fever

Pregnancy and neonates

During pregnancy the dangers to the fetus associated with a primary VZV infection are greater in the first six months. In the third trimester, the mother is more likely to have severe symptoms. For pregnant women,

produced as a result of immunization or previous infection are transferred via the

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

to the

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

. Varicella infection in pregnant women could lead to spread via the placenta and infection of the fetus. If infection occurs during the first 28 weeks of

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

, this can lead to fetal varicella syndrome (also known as ''congenital varicella syndrome''). Effects on the fetus can range in severity from underdeveloped toes and fingers to severe anal and bladder malformation. Possible problems include: * Damage to the brain:

encephalitis Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include se ...

, microcephaly, hydrocephaly, aplasia of brain * Damage to the eye: optic stalk, optic cup, and lens vesicles, microphthalmia, cataracts, chorioretinitis, optic atrophy * Other neurological disorder: damage to cervical and lumbosacral

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

, motor/sensory deficits, absent deep tendon reflexes,

anisocoria Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems. Causes Anisocoria is a common cond ...

/ Horner's syndrome * Damage to body:

hypoplasia Hypoplasia (; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.sphincter dysfunction * Skin disorders: ( cicatricial) skin lesions,

hypopigmentation Hypopigmentation is characterized specifically as an area of Human skin, skin becoming lighter than the baseline skin color, but not completely devoid of skin pigment, pigment. This is not to be confused with depigmentation, which is characterize ...

Infection late in gestation or immediately following birth is referred to as "''neonatal varicella''". Maternal infection is associated with premature delivery. The risk of the baby developing the disease is greatest following exposure to infection in the period 7 days before delivery and up to 8 days following the birth. The baby may also be exposed to the virus via infectious siblings or other contacts, but this is of less concern if the mother is immune. Newborns who develop symptoms are at a high risk of pneumonia and other serious complications of the disease.

Pathophysiology

Exposure to VZV in a healthy child initiates the production of host immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) antibodies; IgG antibodies persist for life and confer immunity. Cell-mediated immune responses are also important in limiting the scope and the duration of primary varicella infection. After primary infection, VZV is hypothesized to spread from mucosal and epidermal lesions to local

sensory nerve A sensory nerve, or afferent nerve, is a nerve that contains exclusively afferent nerve fibers. Nerves containing also motor fibers are called mixed nerve, mixed. Afferent nerve fibers in a sensory nerve carry sensory system, sensory information ...

s. VZV then remains latent in the dorsal ganglion cells of the sensory nerves. Reactivation of VZV results in the clinically distinct syndrome of herpes zoster (i.e., ''shingles''), postherpetic neuralgia, and sometimes Ramsay Hunt syndrome type II. Varicella zoster can affect the arteries in the neck and head, producing stroke, either during childhood, or after a latency period of many years.

Shingles

After a chickenpox infection, the virus remains dormant in the body's nerve tissues for about 50 years. This, however, does not mean that VZV cannot be contracted later in life. The

immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

usually keeps the virus at bay, but it can still manifest itself at any given age causing a different form of the viral infection called shingles (also known as herpes zoster). Since the efficacy of the human immune system decreases with age, the United States Advisory Committee on Immunization Practices (ACIP) suggests that every adult over the age of 50 years get the ''herpes zoster'' vaccine. Shingles affects one in five adults infected with chickenpox as children, especially those who are immune-suppressed, particularly from cancer, HIV, or other conditions. Stress can bring on shingles as well, although scientists are still researching the connection. Adults over the age of 60 who had chickenpox but not shingles are the most prone age demographic.

Diagnosis

The diagnosis of chickenpox is primarily based on the signs and symptoms, with typical early symptoms followed by a characteristic rash. Confirmation of the diagnosis is by examination of the fluid within the vesicles of the rash, or by testing blood for evidence of an acute immunologic response. Vesicular fluid can be examined with a Tzanck smear, or by testing for direct fluorescent antibody. The fluid can also be "cultured", whereby attempts are made to grow the virus from a fluid sample. Blood tests can be used to identify a response to acute infection (IgM) or previous infection and subsequent immunity (IgG). Prenatal diagnosis of fetal varicella infection can be performed using

ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

, though a delay of 5 weeks following primary maternal infection is advised. A PCR (DNA) test of the mother's amniotic fluid can also be performed, though the risk of spontaneous abortion due to the amniocentesis procedure is higher than the risk of the baby's developing fetal varicella syndrome.

Prevention

Hygiene measures

The spread of chickenpox can be prevented by isolating affected individuals. Contagion is by exposure to respiratory droplets, or direct contact with lesions, within a period lasting from three days before the onset of the rash, to four days after the onset of the rash. The chickenpox virus is susceptible to disinfectants, notably chlorine bleach (i.e., sodium hypochlorite). Like all enveloped viruses, it is sensitive to drying, heat and detergents.

Vaccine

Chickenpox can be prevented by vaccination. The side effects are usually mild, such as some pain or swelling at the injection site. A live attenuated varicella vaccine, the Oka strain, was developed by Michiaki Takahashi and his colleagues in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

in the early 1970s. In 1995, Merck & Co. licensed the "Oka" strain of the varicella virus in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and Maurice Hilleman's team at Merck invented a varicella vaccine in the same year. The varicella vaccine is recommended in many countries. Some countries require the varicella vaccination or an exemption before entering elementary school. A second dose is recommended five years after the initial immunization. A vaccinated person is likely to have a milder case of chickenpox if they become infected. Immunization within three days following household contact reduces infection rates and severity in children. Being exposed to chickenpox as an adult (for example, through contact with infected children) may boost immunity to shingles. Therefore, it was thought that when the majority of children were vaccinated against chickenpox, adults might lose this natural boost, so immunity would drop and more shingles cases would occur. On the other hand, current observations suggest that exposure to children with varicella is not a critical factor in the maintenance of immunity. Multiple subclinical reactivations of varicella-zoster virus may occur spontaneously and, despite not causing clinical disease, may still provide an endogenous boost to immunity against zoster. The vaccine is part of the routine immunization schedule in the US. Some European countries include it as part of universal vaccinations in children, but not all countries provide the vaccine. In the UK as of 2014, the vaccine is only recommended in people who are particularly vulnerable to chickenpox. This is to keep the virus in circulation, thereby exposing the population to the virus at an early age when it is less harmful, and to reduce the occurrence of shingles through repeated exposure to the virus later in life. In November 2023, the UK Joint Committee on Vaccination and Immunisation recommended all children be given the vaccine at ages 12 months and 18 months; however, this has not yet been implemented. In populations that have not been immunized or if immunity is questionable, a clinician may order an enzyme

immunoassay An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay ...

. An immunoassay measures the levels of antibodies against the virus that give immunity to a person. If the levels of antibodies are low (low titer) or questionable, reimmunization may be done.

Treatment

Treatment mainly consists of easing the symptoms. As a protective measure, people are usually required to stay at home while they are infectious to avoid spreading the disease to others. Cutting the fingernails short or wearing gloves may prevent scratching and minimize the risk of secondary infections. Although there have been no formal clinical studies evaluating the effectiveness of topical application of calamine lotion (a topical barrier preparation containing

zinc oxide Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, Zinc metabolism, food supplements, rubbe ...

, and one of the most commonly used interventions), it has an excellent safety profile. Maintaining good hygiene and daily cleaning of

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

with warm water can help to avoid secondary bacterial infection; scratching may increase the risk of secondary infection.

Paracetamol Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol. Parac ...

(acetaminophen) but not

aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

may be used to reduce fever. Aspirin use by someone with chickenpox may cause serious, sometimes fatal disease of the liver and brain, Reye syndrome. People at risk of developing severe complications who have had significant exposure to the virus may be given intra-muscular varicella zoster immune globulin (VZIG), a preparation containing high titres of antibodies to varicella zoster virus, to ward off the disease. Antivirals are sometimes used.

Children

If aciclovir by mouth is started within 24 hours of rash onset, it decreases symptoms by one day but does not affect complication rates. Use of aciclovir, therefore, is not currently recommended for individuals with normal immune function. Children younger than 12 years old and older than one month are not meant to receive

antiviral drug Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are a class of antimicrobials ...

s unless they have another medical condition that puts them at risk of developing complications. Treatment of chickenpox in children is aimed at symptoms while the immune system deals with the virus. With children younger than 12 years, cutting fingernails and keeping them clean is an important part of treatment as they are more likely to scratch their blisters more deeply than adults. Aspirin is highly contraindicated in children younger than 16 years, as it has been related to Reye syndrome.

Adults

Infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

in otherwise healthy adults tends to be more severe. Treatment with antiviral drugs (e.g. aciclovir or valaciclovir) is generally advised, as long as it is started within 24–48 hours from rash onset. Remedies to ease the symptoms of chickenpox in adults are generally the same as those used for children. Adults are more often prescribed antiviral medication, as it is effective in reducing the severity of the condition and the likelihood of developing complications. Adults are advised to increase water intake to reduce dehydration and relieve headaches. Painkillers such as paracetamol (acetaminophen) are recommended, as they are effective in relieving itching and other symptoms such as fever or pain. Antihistamines relieve itching and may be used in cases where the itching prevents sleep because they also act as a

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

. As with children, antiviral medication is considered more useful for those adults who are more prone to develop complications. These include pregnant women or people who have a weakened immune system.

Prognosis

The duration of the visible blistering caused by varicella zoster virus varies in children usually from four to seven days, and the appearance of new blisters begins to subside after the fifth day. Chickenpox infection is milder in young children, and symptomatic treatment, with

sodium bicarbonate Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...

baths or

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

medication may ease itching. In adults, the disease is more severe, though the incidence is much less common. Infection in adults is associated with greater morbidity and mortality due to pneumonia (either direct viral pneumonia or secondary bacterial pneumonia),

bronchitis Bronchitis is inflammation of the bronchi (large and medium-sized airways) in the lungs that causes coughing. Bronchitis usually begins as an infection in the nose, ears, throat, or sinuses. The infection then makes its way down to the bronchi. ...

(either viral bronchitis or secondary bacterial bronchitis), hepatitis, and encephalitis. In particular, up to 10% of pregnant women with chickenpox develop pneumonia, the severity of which increases with onset later in gestation. In England and Wales, 75% of deaths due to chickenpox are in adults. Inflammation of the brain, encephalitis, can occur in immunocompromised individuals, although the risk is higher with herpes zoster.

Necrotizing fasciitis Necrotizing fasciitis (NF), also known as flesh-eating disease, is an infection that kills the body's soft tissue. It is a serious disease that begins and spreads quickly. Symptoms include red or purple or black skin, swelling, severe pain, fever ...

is also a rare complication. Varicella can be lethal to individuals with impaired immunity. The number of people in this high-risk group has increased, due to the HIV epidemic and the increased use of immunosuppressive therapies. Varicella is a particular problem in hospitals when there are patients with immune systems weakened by drugs (e.g., high-dose steroids) or HIV. Secondary bacterial infection of skin lesions, manifesting as impetigo,

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

, and

erysipelas Erysipelas () is a relatively common bacterial infection of the superficial layer of the skin ( upper dermis), extending to the superficial lymphatic vessels within the skin, characterized by a raised, well-defined, tender, bright- red rash, ...

, is the most common complication in healthy children. Disseminated primary varicella infection usually seen in the immunocompromised may have high morbidity. Ninety percent of cases of varicella pneumonia occur in the adult population. Rarer complications of disseminated chickenpox include myocarditis,

hepatitis Hepatitis is inflammation of the liver parenchyma, liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), Anorexia (symptom), poor appetite ...

, and glomerulonephritis.Chicken Pox Complications
Hemorrhagic complications are more common in the immunocompromised or immunosuppressed populations, although healthy children and adults have been affected. Five major clinical syndromes have been described: febrile purpura, malignant chickenpox with purpura, postinfectious purpura, purpura fulminans, and anaphylactoid purpura. These syndromes have variable courses, with febrile purpura being the most benign of the syndromes and having an uncomplicated outcome. In contrast, malignant chickenpox with purpura is a grave clinical condition that has a mortality rate of greater than 70%. The cause of these hemorrhagic chickenpox syndromes is not known.

Epidemiology

Primary varicella occurs in all countries worldwide. In 2015 chickenpox resulted in 6,400 deaths globally – down from 8,900 in 1990. There were 7,000 deaths in 2013. Varicella is highly transmissible, with an infection rate of 90% in close contacts. In

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

countries, chickenpox is primarily a disease of children, with most cases occurring during the winter and spring, most likely due to school contact. In such countries it is one of the classic diseases of childhood, with most cases occurring in children up to age 15; most people become infected before adulthood, and 10% of young adults remain susceptible. In the United States, a temperate country, the Centers for Disease Control and Prevention (CDC) do not require state health departments to report infections of chickenpox, and only 31 states volunteered this information . A 2013 study conducted by the social media disease surveillance tool called Sickweather used anecdotal reports of chickenpox infections on social media systems

Facebook Facebook is a social media and social networking service owned by the American technology conglomerate Meta Platforms, Meta. Created in 2004 by Mark Zuckerberg with four other Harvard College students and roommates, Eduardo Saverin, Andre ...

and

Twitter Twitter, officially known as X since 2023, is an American microblogging and social networking service. It is one of the world's largest social media platforms and one of the most-visited websites. Users can share short text messages, image ...

to measure and rank states with the most infections per capita, with Maryland, Tennessee and Illinois in the top three. In the tropics, chickenpox often occurs in older people and may cause more serious disease. In adults, the pockmarks are darker and the scars more prominent than in children.

Society and culture

Etymology

How the term ''chickenpox'' originated is not clear but it may be due to it being a relatively mild disease. It has been said to be derived from ''

chickpea The chickpea or chick pea (''Cicer arietinum'') is an annual plant, annual legume of the family (biology), family Fabaceae, subfamily Faboideae, cultivated for its edible seeds. Its different types are variously known as gram," Bengal gram, ga ...

s'', based on resemblance of the vesicles to chickpeas, or to come from the rash resembling chicken pecks. Other suggestions include the designation ''chicken'' for a child (i.e., literally 'child pox'), a corruption of ''itching-pox'', or the idea that the disease may have originated in chickens.Chicken-pox is recorded in Oxford English Dictionary 2nd ed. since 1684; the OED records several suggested etymologies

Samuel Johnson Samuel Johnson ( – 13 December 1784), often called Dr Johnson, was an English writer who made lasting contributions as a poet, playwright, essayist, moralist, literary critic, sermonist, biographer, editor, and lexicographer. The ''Oxford ...

explained the designation as "from its being of no very great danger".

Intentional exposure

Because chickenpox is usually more severe in adults than it is in children, some parents deliberately expose their children to the virus, for example by taking them to " chickenpox parties". Doctors say that children are safer getting the vaccine, which is a weakened form of the virus, than getting the disease, which can be fatal or lead to shingles later in life. Repeated exposure to chickenpox may protect against zoster.

Other animals

Humans are the only known species that the disease affects naturally. However, chickenpox has been caused in animals, including

chimpanzee The chimpanzee (; ''Pan troglodytes''), also simply known as the chimp, is a species of Hominidae, great ape native to the forests and savannahs of tropical Africa. It has four confirmed subspecies and a fifth proposed one. When its close rel ...

s and

gorilla Gorillas are primarily herbivorous, terrestrial great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or five su ...

Research

Sorivudine, a nucleoside analog, has been reported to be effective in the treatment of primary varicella in healthy adults (case reports only), but large-scale clinical trials are still needed to demonstrate its efficacy. There was speculation in 2005 that continuous dosing of aciclovir by mouth for a period of time could eradicate VZV from the host, although further trials were required to discern whether eradication was actually viable.

References

External links

Prevention of Varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP)
1996
Antiviral therapy of varicella-zoster virus infections
2007
Epidemiology and Prevention of Vaccine-Preventable Diseases: Varicella
US CDC's "Pink Book"

at MedlinePlus {{Authority control Pediatrics Wikipedia medicine articles ready to translate Wikipedia emergency medicine articles ready to translate Vaccine-preventable diseases Airborne diseases Virus-related cutaneous conditions Atypical pneumonias