Chickenpox Classification and external resources
Child with varicella disease
ICD-10 B01 ICD-9 052 DiseasesDB 29118 MedlinePlus 001592 eMedicine ped/2385 derm/74, emerg/367 MeSH C02.256.466.175
Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus (VZV). It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring. On examination, the observer typically finds lesions at various stages of healing.
Chickenpox is an airborne disease spread easily through coughing or sneezing of ill individuals or through direct contact with secretions from the rash. A person with chickenpox is infectious one to two days before the rash appears. The contagious period continues for 4 to 5 days after the appearance of the rash, or until all lesions have crusted over. Immunocompromised patients are probably contagious during the entire period new lesions keep appearing. Crusted lesions are not contagious.
It takes from 10 to 21 days after contact with an infected person for someone to develop chickenpox.
The onset of illness with chickenpox is often characterized by symptoms including myalgia, itching, nausea, fever, headache, sore throat, pain in both ears, complaints of pressure in head or swollen face, and malaise in adolescents and adults. In children, the first symptom is usually the development of a papular rash, followed by development of malaise, fever (a body temperature of 38 °C (100 °F), but may be as high as 42 °C (108 °F) in rare cases), sometimes severe back pains to the lower back, and anorexia (loss of appetite, not to be confused with anorexia nervosa). Typically, the disease is more severe in adults. Chickenpox is rarely fatal, although it is generally more severe in adult males than in adult females or children. Non-immune pregnant women and those with a suppressed immune system are at highest risk of serious complications. Chickenpox is believed to be the cause of one third of stroke cases in children. The most common late complication of chickenpox is shingles, caused by reactivation of the varicella zoster virus decades after the initial episode of chickenpox.
The diagnosis of varicella is primarily clinical, with typical early "prodromal" symptoms, and then the characteristic rash. Confirmation of the diagnosis can be sought through either 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 Tsanck smear, or better with examination 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, 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 developing fetal varicella syndrome.
In temperate countries, chickenpox is primarily a disease of children, with most cases occurring during the winter and spring, most likely due to school contact. It is one of the classic diseases of childhood, with the highest prevalence in the 4–10 year old age group. Like rubella, it is uncommon in preschool children. Varicella is highly communicable, with an infection rate of 90% in close contacts. In temperate countries, most people become infected before adulthood but 10% of young adults remain susceptible.
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 nerves. 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), and sometimes Ramsay Hunt syndrome type II.
Infection in pregnancy and neonates
For pregnant women, antibodies produced as a result of immunization or previous infection are transferred via the placenta to the fetus. Women who are immune to chickenpox cannot become infected and do not need to be concerned about it for themselves or their infant during pregnancy.
Varicella infection in pregnant women could lead to viral transmission via the placenta and infection of the fetus. If infection occurs during the first 28 weeks of gestation, 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 brain: encephalitis, 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, motor/sensory deficits, absent deep tendon reflexes, anisocoria/Horner's syndrome
- Damage to body: hypoplasia of upper/lower extremities, anal and bladder sphincter dysfunction
- Skin disorders: (cicatricial) skin lesions, hypopigmentation
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 prior to delivery and up to 7 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.
After a chickenpox infection, the virus remains dormant in the body's nerve tissues. The immune system keeps the virus at bay, but later in life, usually as an adult, it can be reactivated and cause a different form of the viral infection called shingles (scientifically known as herpes zoster).
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 prior to the onset of the rash, to four days after the onset of the rash. The chickenpox virus (VZV) is susceptible to disinfectants, notably chlorine bleach (i.e., sodium hypochlorite). Also, like all enveloped viruses, VZV is sensitive to desiccation, heat and detergents. Therefore these viruses are relatively easy to kill.
A varicella vaccine was first developed by Michiaki Takahashi in 1974 derived from the Oka strain. It has been available in the U.S. since 1995 to inoculate against the disease. Some countries require the varicella vaccination or an exemption before entering elementary school. Protection from one dose is not lifelong and a second dose is necessary five years after the initial immunization, which is currently part of the routine immunization schedule in the US. The chickenpox vaccine is not part of the routine childhood vaccination schedule in the UK. In the UK, the vaccine is currently only offered to people who are particularly vulnerable to chickenpox. A person who already took the vaccine is more likely to have only a few chickenpox.
Varicella treatment mainly consists of easing the symptoms as there is no actual cure of the condition. Some treatments are however available for relieving the symptoms while the immune system clears the virus from the body. As a protective measure, patients are usually required to stay at home while they are infectious to avoid spreading the disease to others. Also, sufferers are frequently asked to cut their nails short or to wear gloves to prevent scratching and to minimize the risk of secondary infections.
The condition resolves by itself within a couple of weeks but meanwhile patients must pay attention to their personal hygiene. The rash caused by varicella zoster virus may however last for up to one month, although the infectious stage does not take longer than a week or two. Also, staying in a cold surrounding can help in easing the itching as heat and sweat makes it worse.
Although there have been no formal clinical studies evaluating the effectiveness of topical application of calamine lotion, a topical barrier preparation containing zinc oxide and one of the most commonly used interventions, it has an excellent safety profile. It is important to maintain good hygiene and daily cleaning of skin with warm water to avoid secondary bacterial infection. Scratching may also increase the risk of secondary infection.
To relieve the symptoms of chicken pox, people commonly use anti-itching creams and lotions. These lotions are not to be used on the face or close to the eyes. Neem leaves can be made into paste form and can be applied on the rashes. Warm water bath with neem leaves may be helpful. Water bath may be done at least seven days from the onset of the vessicles. It should be done so because the vessicles contains the virus and may splash while bathing and it may cause the vessicles to appear on subsequent regions. An oatmeal bath also might help ease discomfort.
If oral acyclovir is started within 24 hours of rash onset it decreases symptoms by one day but has no effect on complication rates. Use of acyclovir therefore is not currently recommended for immunocompetent individuals (i.e., otherwise healthy persons without known immunodeficiency or on immunosuppressive medication). Children younger than 12 years old and older than one month are not meant to receive antiviral medication if they are not suffering from another medical condition which would put them at risk of developing complications.
Treatment of chickenpox in children is aimed at symptoms whilst the immune system deals with the virus. With children younger than 12 years cutting nails and keeping them clean is an important part of treatment as they are more likely to deep scratch their blisters. 
Infection in otherwise healthy adults tends to be more severe and may be fatal. Treatment with antiviral drugs (e.g. acyclovir or valacyclovir) is generally advised, as long as it is started within 24–48 hours from rash onset. Remedies to ease the symptoms of chicken pox in adults are basically the same as those used on 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. Antiviral medicines do not kill the virus, but stop it from multiplying. Adults are also advised to increase water intake to reduce dehydration and to relieve headaches. Painkillers such as paracetamol and ibuprofen are also recommended as they are effective in relieving itching and other symptoms such as fever or pains. Antihistamines relieve itch and may be used in cases where the itch prevents sleep, because they are also sedative. 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.
Sorivudine, a nucleoside analogue 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.
The duration of the visible blistering caused by varicella zoster virus varies in children usually from 4 to 7 days, and the appearance of new blisters begins to subside after the 5th day. Chickenpox infection is milder in young children, and symptomatic treatment, with sodium bicarbonate baths or antihistamine medication may ease itching. Paracetamol (acetaminophen) is widely used to reduce fever. Aspirin, or products containing aspirin, should not be given to children with chickenpox as it can cause Reye's Syndrome.
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, 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, or encephalitis, can occur in immunocompromised individuals, although the risk is higher with herpes zoster. Necrotizing fasciitis is also a rare complication.
Varicella can be lethal to adults with impaired immunity. The number of people in this high-risk group has increased, due to the HIV epidemic and the increased use immunosuppressive therapies. Varicella is a particular problem in hospitals, especially 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, and erysipelas, 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 also include myocarditis, hepatitis, and glomerulonephritis.
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 etiology of these hemorrhagic chickenpox syndromes is not known.
Chickenpox was first identified by the Persian scientist Muhammad ibn Zakariya ar-Razi (865–925), known to the West as "Rhazes", who clearly distinguished it from smallpox and measles. Giovanni Filippo (1510–1580) of Palermo later provided a more detailed description of varicella (chickenpox).
- ^ Wood MJ (October 2000). "History of Varicella Zoster Virus". Herpes 7 (3): 60–65. PMID 11867004. http://www.ncbi.nlm.nih.gov/pubmed/11867004.
- ^ "Chickenpox". Medline Plus. 2009-09-13. http://www.nlm.nih.gov/medlineplus/ency/article/001592.htm. Retrieved 2011-06-12.
- ^ Centers for Disease Control and Protection (2010-12-27). "Varicella Pink Book Chapter 20 p289 Communicability". http://www.cdc.gov/vaccines/pubs/pinkbook/downloads/varicella.pdf. Retrieved 2010-12-27.
- ^ "General questions about the disease". Varicella Disease (Chickenpox). CDCP. 2001-12-02. http://www.cdc.gov/vaccines/vpd-vac/varicella/dis-faqs-gen.htm. Retrieved 2006-08-18.
- ^ Stroke.ahajournals.org
- ^ Cohen JI, Moskal T, Shapiro M, Purcell RH (December 1996). "Varicella in Chimpanzees". Journal of Medical Virology 50 (4): 289–92. doi:10.1002/(SICI)1096-9071(199612)50:4<289::AID-JMV2>3.0.CO;2-4. PMID 8950684.
- ^ Myers MG, Kramer LW, Stanberry LR (December 1987). "Varicella in a gorilla". Journal of Medical Virology 23 (4): 317–22. doi:10.1002/jmv.1890230403. PMID 2826674.
- ^ McPherson & Pincus: Henry's Clinical Diagnosis and Management by Laboratory Methods, 21st ed., 2007, Chapter 54.
- ^ a b c Royal College of Obstetricians and Gynaecologists (September 2007). "Chickenpox in Pregnancy" (PDF). http://www.rcog.org.uk/files/rcog-corp/uploaded-files/GT13ChickenpoxinPregnancy2007.pdf. Retrieved 2009-07-22.
- ^ Abendroth A, Arvin AM (2001). "Immune evasion as a pathogenic mechanism of varicella zoster virus". Semin Immunol 13 (1): 27–39. doi:10.1006/smim.2001.0293. PMID 11289797.
- ^ Wharton M (1996). "The epidemiology of varicella-zoster virus infections". Infect Dis Clin North Am 10 (3): 571–81. doi:10.1016/S0891-5520(05)70313-5. PMID 8856352.
- ^ "Epidemiology of Varicella Zoster Virus Infection, Epidemiology of VZV Infection, Epidemiology of Chicken Pox, Epidemiology of Shingles". http://virology-online.com/viruses/VZV3.htm. Retrieved 2008-04-22.
- ^ Brannon, Heather (2007-07-22). "Chicken Pox in Pregnancy". Dermatology. About.com. http://dermatology.about.com/cs/pregnancy/a/chickenpreg.htm. Retrieved 2009-06-20.
- ^ "Chickenpox in Pregnancy". March of Dimes. April 2007. http://www.marchofdimes.com/professionals/14332_1185.asp.
- ^ Boussault P, Boralevi F, Labbe L, Sarlangue J, Taïeb A, Leaute-Labreze C (2007). "Chronic varicella-zoster skin infection complicating the congenital varicella syndrome". Pediatr Dermatol 24 (4): 429–32. doi:10.1111/j.1525-1470.2007.00471.x. PMID 17845179. http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0736-8046&date=2007&volume=24&issue=4&spage=429.
- ^ Matsuo T, Koyama M, Matsuo N (July 1990). "Acute retinal necrosis as a novel complication of chickenpox in adults". Br J Ophthalmol 74 (7): 443–4. doi:10.1136/bjo.74.7.443. PMC 1042160. PMID 2378860. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1042160.
- ^ Sauerbrei, Andreas; Wutzler, Peter (December 2001). "Neonatal Varicella". Journal of Perinatology. 21 (8): 545–549.
- ^ NHS.uk
- ^ Patrick R. Murray et al., Medical Microbiology, 5th edition (Elsevier), p.551.
- ^ Chaves SS, Gargiullo P, Zhang JX, et al. (2007). "Loss of vaccine-induced immunity to varicella over time". N Engl J Med 356 (11): 1121–9. doi:10.1056/NEJMoa064040. PMID 17360990.
- ^ , CDC Child & Adolescent Immunization Schedules
- ^ NHS.uk
- ^ "Chickenpox (varicella)". http://www.netdoctor.co.uk/diseases/facts/chickenpox.htm. Retrieved 2010-11-06.
- ^ "Varicella Zoster Virus". http://www.varicellazoster.net/. Retrieved 2010-11-06.
- ^ Tebruegge M, Kuruvilla M, Margarson I (2006). "Does the use of calamine or antihistamine provide symptomatic relief from pruritus in children with varicella zoster infection?" (Abstract). Arch. Dis. Child. 91 (12): 1035–6. doi:10.1136/adc.2006.105114. PMC 2082986. PMID 17119083. http://adc.bmj.com/cgi/content/extract/91/12/1035.
- ^ Domino, Frank J. (2007). The 5-Minute Clinical Consult, 2007. Lippincott Williams & Wilkins. p. 248. ISBN 978-0-7817-6334-9.
- ^ Brannon, Heather (May 21, 2008). Chicken Pox Treatments. About.com.
- ^ Parmet, Sharon; Lynm, Cassio (February 18, 2004). Chickenpox. Journal of the American Medical Association. 291 (7): 906.
- ^ "Chickenpox in Children Under 12". http://www.patient.co.uk/health/Chickenpox-in-Children-Under-12.htm. Retrieved 2010-11-06.
- ^ "Reye's Syndrome-Topic Overview". http://children.webmd.com/tc/reyes-syndrome-topic-overview. Retrieved 2011-03-27.
- ^ "What is chickenpox?". http://www.patient.co.uk/health/Chickenpox-in-Adults-and-Teenagers.htm. Retrieved 2010-11-06.
- ^ "Chickenpox: Treatment & Medication". http://emedicine.medscape.com/article/1131785-treatment. Retrieved 2010-11-06.
- ^ Somekh E, Dalal I, Shohat T, Ginsberg GM, Romano O (2002). "The burden of uncomplicated cases of chickenpox in Israel". J. Infect. 45 (1): 54–7. doi:10.1053/jinf.2002.0977. PMID 12217733.
- ^ US Centers for Disease Control and Prevention. "Varicella Treatment Questions & Answers". CDC Guidelines. CDC. http://www.cdc.gov/vaccines/vpd-vac/varicella/dis-faqs-gen-treatment.htm. Retrieved 2007-08-23.
- ^ Jill M. Baren MD, Philip L. Henneman MD, Roger J. Lewis MD, PhD (August 1996). "Primary Varicella in Adults: Pneumonia, Pregnancy, and Hospital Admissions". Annals of Emergency Medicine 28 (2): 165–169. doi:10.1016/S0196-0644(96)70057-4. PMID 8759580. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WB0-4HG68T8-7&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1152674350&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=079d9dd0e57fad57f6095f23278630aa.
- ^ < ERJ.ersjournals.com
- ^ "Definition of Chickenpox". MedicineNet.com. http://www.medterms.com/script/main/art.asp?articlekey=2702. Retrieved 2006-08-18.
- ^ "Is Necrotizing Fasciitis a complication of Chickenpox of Cutaneous Vasculitis?". atmedstu.com. http://www.atmedstu.com/exam%20plus/Is%20Necrotizing%20Fasciitis%20a%20complication%20of%20Chickenpox%20or%20of%20Cutaneous%20Vasculitis.php. Retrieved 2008-01-18.
- ^ Strangfeld A, Listing J; Herzer, P.; , et al; Liebhaber, A.; Rockwitz, K.; Richter, C.; Zink, A. (2009). "Risk of herpes zoster in patients with rheumatoid arthritis treated With anti–TNF-α agents". J Am Med Assoc 301 (7): 737–744. doi:10.1001/jama.2009.146. PMID 19224750.
- ^ Weller TH (1997). "Varicella-herpes zoster virus". In Evans AS, Kaslow RA. Viral Infections of Humans: Epidemiology and Control. Plenum Press. pp. 865–92. ISBN 978-0306448553.
- ^ a b Chicken Pox Complications
- ^ Otri AM, Singh AD, Dua HS (October 2008). "Abu Bakr Razi". The British Journal of Ophthalmology 92 (10): 1324. PMID 18815419. http://bjo.bmj.com/cgi/pmidlookup?view=long&pmid=18815419. Retrieved 2009-06-20.
Diseases of the skin and appendages by morphology GrowthsPigmentedDermal and
PurpuraMacularthrombocytopenic purpura · actinic purpuraPapularIndurated
Infectious skin disease: Viral cutaneous conditions, including viral exanthema (B00–B09, 050–059)HSV (Herpes simplex, Herpetic whitlow, Herpes gladiatorum, Herpetic keratoconjunctivitis, Herpetic sycosis, Neonatal herpes simplex, Herpes genitalis, Herpes labialis, Eczema herpeticum, Herpetiform esophagitis) · Herpes B virus (B virus infection)OtherPapillomaviridae Ungroupedunknown/multiple: Asymmetric periflexural exanthem of childhood · Post-vaccination follicular eruption · Lipschütz ulcer · Eruptive pseudoangiomatosis · Viral-associated trichodysplasia · Gianotti–Crosti syndrome Varicella zoster Infections Other
Wikimedia Foundation. 2010.
Look at other dictionaries:
chickenpox — ► NOUN ▪ an infectious disease causing a mild fever and a rash of itchy inflamed pimples; varicella. ORIGIN probably so named because of its mildness, as compared to smallpox … English terms dictionary
chickenpox — [chik′ənpäks΄] n. an acute, contagious viral disease, usually of young children, characterized by fever and eruptions; varicella … English World dictionary
chickenpox — /chik euhn poks /, n. a disease, commonly of children, caused by the varicella zoster virus and characterized by mild headache and fever, malaise, and eruption of blisters on the skin and mucous membranes. Also, chicken pox. Also called varicella … Universalium
chickenpox — SYN: varicella. * * * n. a highly infectious disease caused by a herpesvirus (the varicella zoster virus) that is transmitted by airborne droplets. After an incubation period of 11 18 days a mild fever develops, followed after about 24 hours by… … Medical dictionary
chickenpox — n. to catch, come down with (the) chickenpox * * * [ tʃɪkɪnpɒks] come down with (the) chickenpox to catch … Combinatory dictionary
chickenpox — chick|en|pox [ tʃıkən,paks ] noun uncount an infectious disease that most children get once, in which the skin is covered with red spots. Chickenpox is a more serious disease in adults … Usage of the words and phrases in modern English
chickenpox — [[t]tʃɪ̱kɪnpɒks[/t]] also chicken pox N UNCOUNT Chickenpox is a disease which gives you a high temperature and red spots that itch … English dictionary
chickenpox — n. a highly infectious disease caused by a herpesvirus (the varicella zoster virus) that is transmitted by airborne droplets. After an incubation period of 11–18 days a mild fever develops, followed after about 24 hours by an itchy rash of red… … The new mediacal dictionary
chickenpox — UK [ˈtʃɪkɪnˌpɒks] / US [ˈtʃɪkənˌpɑks] noun [uncountable] an infectious disease that most children get once, in which the skin is covered with red spots. Chickenpox is a more serious disease in adults … English dictionary
Chickenpox — … Википедия