The initial prodromal phase of varicella consists of malaise and low grade fever. Fever is rarely above 102 F. The characteristic feature of varicella is the formation of cutaneous vesicles. Exanthem develops over 3 to 6 days. Usually it begins along the hairline on the face as red macules that progress to tiny vesicles with surrounding erythema. It is often described as “dew drops on a rose petal”. The vesicles then form pustules which become crusted and scabbed over. The rash appears in successive crops over the trunk and then the extremities. In the first week, there are lesions in different stages of development. By the end of the first week, the fever subsides and the cutaneous lesions start crusting, become dry and fall off. Eventually they heal leaving no scar behind.

Complications of varicella include the following:

• Bacterial infection: Bacterial infection of a vesicular lesion is the most frequent complication of varicella. Common bacteria infecting the vesicles include group A streptococci and staphylococci. Less common but more serious bacterial infections are toxic shock syndrome, sepsis, cellulitis, erysipelas, cutaneous abscesses, impetigo and suppurative lymphadenitis. 
• Viral sequelae: Viral sequelae of varicella may involve all systems. Most common are pneumonitis, hepatitis, arthritis, pericarditis, glomerulonephritis, orchitis and involvement of the central nervous system (such as encephalitis).
• Purpura fulminans: Purpura fulminans is a large ecchymosis that appears on the legs. Occasionally, it may progress to hemorrhagic gangrene. 

• Fever

  Manifestations include a characteristic rash, fever, malaise and headache. The initial prodromal phase of varicella consists of malaise and low grade fever. Fever is rarely above 102 F. [symptoma.com]

  Over-the-counter Medications Use non-aspirin medications, such as acetaminophen, to relieve fever from chickenpox. Do not use aspirin or aspirin-containing products to relieve fever from chickenpox. [web.archive.org]

  Instead, use non-aspirin medications, such as acetaminophen, to relieve fever from chickenpox. [cdc.gov]

  The most frequent solicited local adverse event after MMRV vaccine is redness, and fever is the most common solicited general symptom. [ncbi.nlm.nih.gov]

• Malaise

  Manifestations include a characteristic rash, fever, malaise and headache. The initial prodromal phase of varicella consists of malaise and low grade fever. Fever is rarely above 102 F. [symptoma.com]

  In healthy children, varicella is generally mild, with an itchy rash, malaise, and temperature up to 102°F for 2 to 3 days. [web.archive.org]

  Prodromal symptoms consist of low-grade fever, headache, anorexia, and malaise. On the following day, the characteristic rash begins to appear. The lesions evolve from erythematous macules to form small papules. [medicinenet.com]

  It is characterized by an itchy, vesicular rash, usually starting on the scalp and face, initially accompanied by fever and malaise. As the rash gradually spreads to the trunk and extremities, the first vesicles dry out. [who.int]

  The child may have low grade fever, malaise, and headache. The severity of infection is dependent on the age of the patient. The older the patient the more severe the infection can be. [aocd.org]

• Fatigue

  Mental fatigue can manifest as somnolence, lethargy, or directed attention fatigue.[4] Fatigue and 'feelings of fatigue' are sometimes confused.[5] Unlike weakness, fatigue usually can be alleviated by periods of rest. [en.wikipedia.org]

  She presented clinically with sudden onset of fatigue, vertigo, nausea and epileptic seizures. Investigations of the cerebrospinal fluid revealed 522/3 cells, lactate 2.9 mmol/L, protein 232 mg/dL and 2.4 × 10 3 varicella zoster virus. [ncbi.nlm.nih.gov]

  Symptoms Generalized red, itchy vesicles on the trunk and face that spread to the extremities Fever Fatigue Cough Varivax Vaccine The Varivax vaccine is used to protect against chickenpox. It is effective in 70-90% of those who receive the vaccine. [students.case.edu]

  Chickenpox: A highly infectious viral disease also known medically as varicella -- in many countries, this disease is always called "varicella" -- that causes a blister-like rash, itching, fatigue and fever. [medterms.com]

  Definition of Chickenpox Chickenpox: A highly infectious viral disease also known medically as varicella -- in many countries, this disease is always called "varicella" -- that causes a blister-like rash, itching, fatigue and fever. [web.archive.org]

• Low Fever

  Patients typically are afebrile or have low fever and develop fewer than 50 skin lesions. They usually have a shorter illness compared to unvaccinated people who get varicella. [web.archive.org]

  They may include: Pain, swelling, and redness where the shot was given Mild rash Low fever Serious side effects from the chickenpox vaccine are very rare. [vaccines.gov]

  Illness is usually mild (low fever or no fever, fewer lesions [less than 50], less pruritic, shorter duration, absence of vesicles), although some patients present similar to unvaccinated individuals. [visualdx.com]

  Although the lesions may appear alarming, varicella in children is usually a mild disease with few complications and a low fever. Occasionally, if the rash is severe, the fever may be higher. [encyclopedia.com]

• El Salvador

  We present a case of a previously healthy human immunodeficiency virus-negative 26-year-old immigrant from El Salvador in whom primary varicella developed that rapidly progressed to fulminant hepatic failure, disseminated intravascular coagulation, and [ncbi.nlm.nih.gov]

  We present a case of a previously healthy human immunodeficiency virus—negative 26-year-old immigrant from El Salvador in whom primary varicella developed that rapidly progressed to fulminant hepatic failure, disseminated intravascular coagulation, and [archinte.jamanetwork.com]

• Cough

  The virus spreads from person to person by direct contact or through the air by coughing or sneezing. It takes from 10-21 days after contact with an infected person for someone to develop chickenpox. [medterms.com]

  Early symptoms are similar to that of the common cold, which include mild fever, coughing, a runny nose, and watery eyes. As the disease progresses, the coughing gets worse; problems with coughing can last from six to 12 weeks. [immunize.ca]

  The main presenting symptoms were itchy skin rash, fever, cough, sputum, breathlessness, throat pain, vomiting, abdominal pain, confusion and headache. [ncbi.nlm.nih.gov]

• Heart Disease

  Children under 5 years of age Pregnant women People with chronic conditions such as: heart disease, liver disease, kidney disease, blood disorders diabetes, severe obesity, asthma and chronic lung disease, neurological disorders, cancer or immune-compromising [immunize.ca]

  Oral aciclovir should be started for 5-7 days (800 mg x 5 daily for adults, 20 mg/kg up to 800 mg qds for children) in the following: Patients with a chronic medical condition (lung or heart disease, for example). [patient.info]

  The additional risk factors included: congenital heart disease (5% versus 23%), migraines (10% versus 10%), other vasculopathies (0% versus 21%), presence of anticardiolipin antibody (33% versus 36%), and other (1% versus 14%). [stroke.ahajournals.org]

• Anisocoria

  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 [en.wikipedia.org]

• Blurred Vision

  Such inflammatory changes and chorioretinal scarring may, in turn, result in blurred vision and abnormal sensitivity to light (photophobia). [rarediseases.org]

• Skin Rash

  Pleomorphic itchy skin rash and fever were the most common presenting symptoms; however three patients presented with history of recent skin rash which subsided at the time of presentation and these patients presented with neurological complication of [web.archive.org]

  Children can spread the virus from one day before they show signs of illness to about five days after a skin rash appears. [my.clevelandclinic.org]

  The main presenting symptoms were itchy skin rash, fever, cough, sputum, breathlessness, throat pain, vomiting, abdominal pain, confusion and headache. [ncbi.nlm.nih.gov]

  Common symptoms include fever and a blister-like skin rash. Herpes zoster, or shingles, is a painful rash that can occur many years following chickenpox. [publichealthontario.ca]

• Eruptions

  There are practically no premonitory symptoms, though slight fever for about 24 hours may precede the eruption. [britannica.com]

  These patients often have a more extensive (disseminated) and atypical eruption (often with purpura and hemorrhagic vesicles) as well as visceral involvement (CNS, lung, liver). [visualdx.com]

  Upon examination, the child was found to have a zosteriform radicular pattern of skin eruption corresponding to dermatomes C6, C7, and C8. The eruption was patchy, flat, nonblistering, and eczematous. [bcmj.org]

  The eruption may be generalized (in severe cases) involving the trunk, extremities, and face, or more limited but almost always involves the upper trunk. [msdmanuals.com]

  The incubation period is from 10 to 21 days (most commonly 14 to 16) The illness has a short prodrome of fever, lethargy and anorexia followed by eruption of the rash that occurs over the next three to five days. [rch.org.au]

• Eczema

  Allergic rhinitis, asthma, and atopic eczema are among the commonest causes of chronic ill health. These diseases are increasing in prevalence, and they add considerably to the burden of health care costs. [doi.org]

  Antiviral medicine may be very important for those who have skin conditions (such as eczema or recent sunburn), lung conditions (such as asthma), or who have recently taken steroids. [nlm.nih.gov]

  Give oral valacyclovir or famciclovir to varicella patients ≥ 12 years and to those with skin disorders (particularly eczema) or chronic lung disease. Give IV acyclovir to immunocompromised patients and to other patients at risk of severe disease. [msdmanuals.com]

  Aciclovir is indicated in children with impaired immunity, certain neonates (see diagram), and possibly severe eczema. [rch.org.au]

• Vesicular Rash

  The diagnosis of varicella is usually made on clinical grounds on the basis of the characteristic vesicular rash. The following investigations may be helpful in establishing the diagnosis if clinical examination is not sufficient. [symptoma.com]

  Abstract The earliest reports of vesicular rashes of the type we now recognize to be caused by herpes simplex and zoster date to the ancient civilizations. [ncbi.nlm.nih.gov]

• Pruritus

  Her mother reports that she is scratching continuously and has had very little sleep over the past few days as a result of the pruritus. [web.archive.org]

  Figures and Tables - Analysis 2.10 Comparison 2 Zoster vaccine versus placebo subgroup analysis by age, Outcome 10 Pruritus inoculation site. [dx.doi.org]

  At the blister stage, intense pruritus is present. Blisters may occur on the palms, soles, and genital area. [ncbi.nlm.nih.gov]

• Withdrawn

  In Mills 2010, Oxman 2005 and Vermeulen 2012 consent was withdrawn after intervention. [dx.doi.org]

• Headache

  Headache Other names Cephalalgia Person with a headache Specialty Neurology Headache is the symptom of pain in the face, head, or neck. [en.wikipedia.org]

  Manifestations include a characteristic rash, fever, malaise and headache. The initial prodromal phase of varicella consists of malaise and low grade fever. Fever is rarely above 102 F. [symptoma.com]

  Symptoms can include a headache, sensitivity to light, neck stiffness and pain, delirium, and seizures. [dermatology.about.com]

  We report an unusual case of an immunocompetent young adult presenting with occipital headache and zoster rash, without preherpetic and postherpetic neuralgia, who was diagnosed with varicella meningitis on Polymerase chain reaction (PCR). [ncbi.nlm.nih.gov]

  Other typical symptoms that may begin to appear 1-2 days before rash include: high fever tiredness loss of appetite headache Children usually miss 5 to 6 days of school or childcare due to their chickenpox. [web.archive.org]

• Cerebellar Ataxia

  Although chickenpox has a good prognosis, neurologic complications including encephalitis, acute cerebellar ataxia, myelitis and meningitis may seldom be associated with the disease. [ncbi.nlm.nih.gov]

  Serious complications from chickenpox include dehydration pneumonia bleeding problems infection or inflammation of the brain (encephalitis, cerebellar ataxia) bacterial infections of the skin and soft tissues in children including Group A streptococcal [web.archive.org]

  Acute postinfectious cerebellar ataxia is one of the most common neurologic complications; it occurs in 1/4000 cases in children. [msdmanuals.com]

• Febrile Seizures

  Febrile seizures occurred after dose 1 of MMR vaccine at a known low increased risk (RI, 2.71; 95% CI, 1.71- 4.29). [ncbi.nlm.nih.gov]

  Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures. Pediatrics. 2010;126:e1–e8. 51. Schink T, Holstiege J, Kowalzik F, et al. [journals.lww.com]

  There is a very small risk of febrile seizures after vaccination. [kidshealth.org]

  If you decide to vaccinate for varicella, DO NOT opt for the ProQuad vaccine (both MMR and Varicella combined), as this vaccine is associated with higher rates of febrile seizures and fever. [drgreenmom.com]

• Guillain-Barré Syndrome

  Disseminated primary varicella infection; this carries high morbidity Central nervous system complications such as Reye syndrome, Guillain-Barré syndrome and encephalitis Thrombocytopenia and purpura Varicella in pregnancy Non-immune pregnant women should [dermnetnz.org]

  Rare central nervous system complications include aseptic meningitis, encephalitis, transverse myelitis and Guillain-Barré syndrome. [healio.com]

  Nervous/Psychiatric: Encephalitis; cerebrovascular accident; transverse myelitis; Guillain-Barré syndrome; Bell’s palsy; ataxia; non-febrile seizures; aseptic meningitis; dizziness; paresthesia. Respiratory: Pharyngitis; pneumonia/pneumonitis. [drgreenmom.com]

  Rare complications of varicella include aseptic meningitis, transverse myelitis, Guillain-Barré syndrome, thrombocytopenia, hemorrhagic varicella, purpura fulminans, glomerulonephritis, myocarditis, arthritis, orchitis, uveitis, iritis, and hepatitis. [cdc.gov]

The diagnosis of varicella is usually made on clinical grounds on the basis of the characteristic vesicular rash. The following investigations may be helpful in establishing the diagnosis if clinical examination is not sufficient.

• Blood count: White blood cells are usually normal or low. Increase in the number of white blood cells suggests secondary bacterial infection. 
• Chest X-ray: In case of varicella pneumonitis, numerous bilateral nodular opacities may be seen in X-rays of the chest. Hyperinflation may also be apparent.
• Viral sampling and cell culture: Varicella zoster virus may be identified by obtaining samples of the fluid in the vesicles and for inoculation in cell culture.
• Immunological tests: The most reliable methods for testing varicella zoster humoral immunity are fluorescent antibody to membrane antigen (FAMA) and enzyme linked immunosorbent assay (ELISA) [3]. 

• Human Herpesvirus 3

  Varicella, the primary infection with varicella-zoster virus (VZV; human herpesvirus 3), in pregnancy may cause maternal mortality or serious morbidity. [rcog.org.uk]

  None have yet been reported in varicella-zoster virus (VZV; also known as human herpesvirus 3 [HHV-3]). [ncbi.nlm.nih.gov]

  Human herpesvirus 3 Human herpesvirus 3 [X04370=NC_001348] (HHV-3) (Varicella-zoster virus) ^ "Pathogen Safety Data Sheets: Infectious Substances – Varicella-zoster virus". canada.ca. [en.wikipedia.org]

In a healthy child, varicella is not a serious disease. The treatment of varicella consists of the following components.

• Maintenance of hydration: It is important to maintain hydration in the children suffering from varicella.
• Good hygiene: General good hygiene should be maintained by keeping the nails trimmed and keeping the skin clean. This reduces itching and the likelihood of damaging the skin due to sharp nails.
• Antipyretics: Paracetamol is the antipyretic used to control the low grade fever of paracetamol. Aspirin should be avoided to avoid the risk of Reye’s syndrome.
• Calamine lotion: Calamine lotion may be applied on the skin to relieve the severe itching associated with varicella. 
• Diphenhydramine syrup: In case of uncontrolled itching and discomfort, diphenhydramine syrup may be given to provide adequate relief.
• Antibiotics: In case of secondary infection of the skin, antibiotic therapy is necessitated. 
• Varicella zoster immunoglobulin (VZIG): Varicella zoster immunoglobulin (VSIG) may be given in the children who are immunocompromised or who are receiving corticosteroid therapy for any other condition [4] [5].
• Acyclovir: In case of varicella infection, there is no beneficial effect of varicella zoster immunoglobulin after 4th day post-exposure. In such cases, acyclovir is given for 7 days in a total daily dose of 1500 mg per square meter of surface area. Intravenous acyclovir blocks further viral replication within 24 to 48 hours. Such early treatment prevents the development of progressive varicella and its associated complications [6] [7].

Varicella is not a very serious disease and therefore, the prognosis is usually good. The mortality depends upon the health and the age of the child. The mortality rate of children suffering from varicella is around 1 in 50,000 children. In infants, the mortality is much higher at 1 in 13,000 children. Children on high dose steroid therapy have a greater risk of developing complications of varicella. Mortality from varicella has declined in the United States since the implementation of vaccination [2].

Varicella is caused by one of the human herpes viruses; specifically varicella zoster virus (VZV). Varicella zoster virus is a DNA virus and is transmitted by droplets in respiratory secretions. Air currents from an infected child to a susceptible child carry these water droplets. Varicella is contagious from 24 to 48 hours before the rash appears and while uncrusted vesicles are present – which is around 3 to 7 days.

Varicella is a common disease of children. It occurs equally in all races and genders [1].

After a susceptible child receives the virus, there is an incubation period of around 10 to 20 days before the appearance of the characteristic vesicular rash. The initial site of infection is the conjunctivae or the upper respiratory tract. The virus then replicates for about 4 to 6 days at a local site in the head or neck. Thereafter, the virus is transmitted throughout the body which is known as primary viremia. One week later, the virus is released in large amounts after a second replication. This is known as secondary viremia. The virus then leaves the capillaries and invades the epidermis of the skin. The characteristic vesicles of varicella then appear on the skin.

Varicella can be prevented by the use of varicella vaccine [8]. Varicella vaccine is not recommended below the age of 1 year. After the age of one year, a single dose of 0.5 ml is recommended. Herpes zoster may also be prevented in adults by the use of varicella vaccine [9] [10]. Infection with varicella confers lifelong immunity in the host.

Varicella, more commonly known as chicken pox, is a common exanthem of the pediatric population. It is caused by varicella zoster virus. The salient features of varicella are malaise, rash, fever and headache. After recovery from the initial infection, the virus still remains in a latent state within the dorsal root (sensory) ganglion cells. In around 10 to 15% of the cases, the virus may reactivate in old age when the immune system becomes weak. In such cases, there is a characteristic exanthem in a dermatomel pattern which is referred to as herpes zoster or shingles.

Varicella is a common infectious disease of children and is known as chicken pox. It is caused by a virus and is characterized by the formation of rash. It is not a serious disease but prompt treatment is necessary to prevent the development of complications.

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7. Vilde JL, Longuet P. [Acyclovir and infections caused by varicella-zoster viruses]. La Revue du praticien. Oct 15 1994;44(16):2133-2136.
8. Dennehy PH. Varicella vaccine for prevention of chickenpox. Rhode Island medicine. Jan 1995;78(1):14-16.
9. Hambleton S. Prevention of varicella and zoster by live attenuated VZV vaccine. Frontiers in bioscience : a journal and virtual library. 2008;13:2696-2704.
10. Caple J. Varicella-zoster virus vaccine: a review of its use in the prevention of herpes zoster in older adults. Drugs of today. Apr 2006;42(4):249-254.