VIRAL EXANTHEMS

Sahara Tuazan AbonawasClass 2013

EXANTHEM

A widespread rash that is usually accompanied by systemic symptoms

usually caused by an infectious condition represents either a

o reaction to a toxin produced by the organismo damage to the skin by the organismo an immune response

Enanthem - Discrete lesions found at the buccal mucosa

Most common childhood viral exanthems:

Rubeola (Measles or “First disease”) Rubella (German Measles or “Third disease”) Erythema infectiosum (“Fifth disease”) Roseola infantum (Exanthem subitum or “Sixth disease”) Varicella (Chickenpox)

ViralExanthem

Etiology Incubation period (days)

Prodromal period (days)

Rash Complications

Rubeola (Measles)

Measles virus

10-12 3-5 Maculopapular, starts on head and progresses

caudally

Otitis media, Pneumonia, Encephalitis

Rubella (German Measles)

Rubella virus

14-21 shorter than that

of measles

Discreet maculopapular rash that begins on the

face and spreads quickly

Relatively uncommon to children

Erythema infectiosum

(“Fifth disease”)

Parvovirus 4-28 “Slapped cheeks” then reticular erythematous

macupapular rash beginning on arms then

to the trunk and legs

Roseola infantum

(“Sixth disease”)

HHV-6HHV-7

5-15 Discreet maculopapular that starts on trunk and spreads to extremities

Varicella (Chickenpox)

Varicella virus

10-21 Pruritic “teardrop” shaped vesicles that break and crust over beginning on face or

trunk and spreading to extremities

Bacterial super-infection, Pneumonia, Encephalitis, Bleeding disorders, Congenital infection, Life-threatening perinatal infection

RUBEOLA (Measles)

Definition

An acute viral infection characterized by a final stage with maculopapular rash erupting over the neck and face, trunk, arms and legs accompanied by high fever

EtiologyMeasles virus

- an RNA virus of genus Morbillivirus, family Paramyxoviridae

- only one serotype is known- shed in nasopharyngeal secretions,

blood, and urine during the prodromal period and for a short time after the rash appears

- can remain viable for at least 34 hr at room temperature.

EpidemiologyEndemic throughout the world

Peak age incidence = 5-10 y/o

But now occurs most often in unimmunized preschool-aged children

Transmission

Highly contagious approximately 90% of susceptible family

contacts acquire the diseaseMaximal dissemination of virus

- occurs by droplet spray during the prodromal period (catarrhal stage)

PathogenesisEssential lesion of measles

- found in the skin, conjunctivae, and the mucous membranes of the nasopharynx, bronchi, and intestinal tract

Serous exudate and proliferation of mononuclear cells and a few polymorphonuclear cells

- occur around the capillariesHyperplasia of lymphoid tissue

- usually occurs, particularly in the appendix, where multinucleated giant cells of up to 100 μm in diameter (Warthin-Finkeldey reticuloendothelial giant cells) may be found

Particularly notable about the sebaceous glands and hair follicles in the skin Koplik spots

- consist of serous exudate and proliferation of endothelial cells similar to those in the skin lesionsA general inflammatory reaction of the buccal and pharyngeal mucosa

- extends into the lymphoid tissue and the tracheobronchial mucous membrane

Clinical ManifestationsThree clinical stages:

Incubation stage

Prodromal stage with an enanthem (Koplik spots) and mild symptoms

Final stage with a maculopapular rash accompanied by high fever

Incubation stage lasts approximately 10-12 days to the first prodromal symptoms and another 2-4 days to the appearance of the rashmay be as short as 6-10 daysBody temperature

- may increase slightly 9-10 days from the date of infection and then subside for 24 hr or soPatient

- may transmit the virus by the 9th-10th day after exposure and occasionally as early as the 7th day, before the illness can be diagnosed

Prodromal stage

Lasts 3-5 days characterized by

o low-grade to moderate fevero dry cough o coryzao conjunctivitis o an enanthem (Koplik spots)o Usually with photophobia

May be severe with sudden high fever and pneumonia

An enanthem or red mottling is usually present on the hard and soft palates

Koplik spots

grayish white dots, usually as small as grains of sand, that have slight, reddish areolae

occasionally they are hemorrhagic

tend to occur opposite the lower molars but may spread irregularly over the rest of the buccal mucosa

found within the midportion of the lower lip, on the palate, and on the lacrimal caruncle rarely

appear and disappear rapidly, usually within 12-18 hr

Transverse line of conjunctival inflammation- sharply demarcated along the eyelid margin- may be of diagnostic assistance in the prodromal stage- disappears as the entire conjunctiva becomes involved

Final stage

The temperature rises abruptly as the rash appears and often reaches 40°C (104°F) or higher

Symptoms - subside rapidly as the rash appears on the legs and feet within about 2 days, usually with an abrupt drop in temperature to normal

Within 24 hr after the temperature drops: Patients appear well

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Koplik spotsFever

Dry coughCoryza

Conjunctivitis

RashT

E

M

P

Rash - starts as faint macules in the upper lateral parts of the neck, behind the ears, along the hairline, posterior parts of the cheek

First 24 hour:Maculopapular rash

-spreads rapidly over the entire face, neck, upper arms, & upper part of the chest

2nd day : Rash – spreads over the

back, abdomen, entire arm, & thighs

2nd-3rd day:Rash - reaches the feet and

concomitantly rash begins to fade on the faceBranny desquamation &

brownish discoloration as the rash fades and disappears within 7 days

DiagnosisBased on clinical featuresMeasles IgM antibodies—detected for 1 month

after illnessMultinucleated giant cells can be demonstrated

in smears of nasal mucosa during prodromal stage

WBC-with Leukopenia & a relative lymphocytosisCSF - increase in protein, small increase in

lymphocytes, and normal level of glucose

Treatment

NO specific antiviral therapy

Treatment is primarily supportiveAntipyretics for feverBed restMaintenance of adequate fluid intakeAppropriate antimicribial therapy

PrognosisCase fatality rate = 1-3/1000 cases (USA) Deaths 10 due to pneumonia or 20 bacterial

infectionsDeveloping countries:

frequently occurs in infants; possibly because of concomitant malnutrition

disease - very severe and has a high mortality

PreventionIsolation precautions – 7th day after exposure until 5 days

after the rash has appeared

Active immunization1ST dose recommended at 12-15 mo af age2ND dose at 4-6yrs of age or after 4 wks of 1st doseContraindications: pregnant women, children with primary

immunodeficiency, untreated tuberculosis, cancer, or organ transplantation, those receiving long-term immunosuppressive therapy, or severely immunocompromised HIV-infected children

Passive immunization Effective for prevention within 6days of exposureImmune globulin - <12 mo of age: 0.25mL/kg max. 15 mlImmunocompromised: 0.5mL/kg max 15 ml

RUBELLA(German or Three-day measles)

Definition

An acute viral infection characterized by mild constitutional symptoms, a rash similar to mild rubeola or scarlet fever, enlargement of postoccipital, retroauricular and posterior cervical lymph nodes

Etiology

Rubella virus - an RNA Virus of genus Rubivirus in the

family Togaviridae

EpidemiologyHumans - the only natural host Virus

- spread by oral droplet or transplacentally- present in nasopharyngeal secretions, blood, feces,

and urine- shed in nasopharyngeal secretions, blood, feces, and

urine- has been recovered from the nasopharynx 7 days

before exanthem and 7-8 days after its disappearanceDistributed worldwideAffects both sexes equallyPeak incidence in children: 5-14 yrs old

But most cases now occur among susceptible teenagers and young adults

Clinical ManifestationsIncubation period : 14-21 daysProdromal phase

characterized by mild catarrhal symptomsshorter than that of measlesMost characteristic sign: retroauricular, post

cervical, postoccipital lymphadenopathy - evident at least 24 hr before the rash appears and may remain for 1 wk or more

Forchheimer spots

- enanthem- appears just before the onset of skin rash - discrete rose spots on the soft palate which coalesce into red bluish & extend over the fauces

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Rash

Temperature

Adenitis

ExanthemMore variableBegins on the face and spreads

quicklywithin 24 hrs:

Discreet maculopapules present in large number

Large areas of flushing – spread rapidly over entire body usually

2nd day : pinpoint appearance with mild itching

3rd day : eruption with minimal desquamation

No photophobiaFever is low grade or absent during the

rash and persist for 1-3 daysAnorexia, headache, and malaise - not

common

Diagnosis

Evident at clinical symptoms and historyConfirmed by serology, virus culture from

nasopharyngeal secretions and bloodWBC = normal or decreasedIgM antibodies are detected in first few days

of illness

TreatmentNo specific antiviral therapyTreatment is entirely supportive

Antipyretics (acetaminophen or Ibuprofen) are indicated for fever

Prognosis Excellent

Prevention MMR vaccine

1st dose: 12-15 mos2nd dose: anytime at childhood (4-6yr)

orafter 4 wks of first dose

Pregnant patients should not be given rubella vaccine and females should avoid becoming pregnant for 3 months after vaccination

ROSEOLA INFANTUM (Exanthem subitum)

Definition

A mild febrile, exanthematous illness occuring almost exclusively during infancy (peak: 6-15 months of age)

Etiology

Herpesvirus-6 (HHV-6)and Herpesvirus-7 (HHV-7)

β- herpes virus subfamily of herpes virus

Epidemiology

Primary infection with HHV-6 occurs early in life> 90% of newborn infants are (+) HHV-6By 4-6 months old prevalence drops to 0-60%Peak acquisition is at 6-15 months old

Primary infection with HHV-7 occurs later 90% at 7-10 yrs old

TransmissionVirus - probably acquired from the saliva of healthy

persons and enters the host through the oral, nasal, or conjunctival mucosa

Most adults excrete HHV6 and HHV7 in saliva and women excrete them in genital tract

HHV6 can be transmitted in uteroNO evidence that infection can be transmitted in

breastmilk

Clinical Manifestations

Incubation Period - averages 10 days (5-15 days)

Prodromal Period - usually asymptomatic but may include mild upper respiratory tract signs

* minimal rhinorrhea* slight pharyngeal inflammation* mild conjunctival redness

Clinical Illness is heralded by a febrile stage: Temperature (37.9-400C) for 3-5 days then

typically resolves abruptly (‘crisis”) or occasionally gradually over 24-36 hrs (‘lysis”)

Irritable and anorexicSeizures occur (5-10%)

Nagayama spots - ulcers at uvulopalataoglossal junction common in infants in Asian countries

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Temperature

Febrile StageFebrile Stage

Rash

Rash oappears 12-24 hrs of resolution of feverorose colored, fairly distinctiveodiscrete, small (2-5mm), slightly raised pink

lesions on the trunk which spreads to the neck, face, and proximal extremities

onot usually pruriticono vesicles or pustules developso fades after 1-3 days

DiagnosisCan be established based on age, history and

clinical findingsLab findings:

WBC = 8,000-9,000 during first few days and then decreases with appearance of rash

May perform specific HHV6 serologic testing IgM develops by 5th to 7th day of illness and

resolves within 2 monthsSeroconversion 4x = positive result

TreatmentHHV-6 - inhibited by ganciclovir, cidofovir,

foscarnet

HHV-7 - inhibited by cidofovir, foscarnet

Supportive treatmentChildren at pre-eruptive stage may benefit

from Acetaminophen and Ibuprofen

PrognosisExcellent

PreventionNo vaccine has been developed

Erythema infectiosum(Fifth disease)

DefinitionA benign, self-limited exanthematous

illness of childhood

Etiology

Caused by Parvovirus B19, which are small DNA viruses of the genus Erythrovirus in the family Parvoviridae

Replicate in mitotically active cells

Epidemiology

Common and worldwideClinically apparent infections are most

prevalent in school-aged children (5 and 15 years of age)with 70% of cases occurring between 5-15

yrs old

Transmission Via exposure to fluid from the nose (respiratory

secretions)Also transmissible in blood and blood products

Transmission rate in household contacts is from15-30%Mothers more commonly affected than fathers

Children no longer infectious by the time they have developed a rash

Clinical ManifestationsIncubation period

Ranges from 4 to 28 days (average 16-17 days)

Prodromal phasemildConsist of low-grade fever, headache and symptoms of

URTI

Final StageHallmark : characteristic rash

Initial stage : erythematous facial flushing, described as "slapped-cheek appearance“

Rash

spreads rapidly or concurrently to the trunks and proximal extremities as diffuse macular erythemaCentral clearing of macular lesions

- occurs promptly, giving the rash a lacy, reticulated appearance

Characteristic sparing of palms and soles

resolves spontaneously without desquamation but tends to wax and wane over 1-3 weeks

can recur with exposure to sunlight, heat, exercise and stress

DiagnosisUsually based on clinical presentation of the typical rash

and exclusion of other conditions

Serologic test for B19• B19 specific IgM develops rapidly after infection and persist

for 6-8wks

TreatmentNo specific antiviral therapy

Prognosis EXCELLENT

VARICELLA(Chicken Pox)

Definition an acute febrile rash illness, common in children who have not been immunized

variable severity but is usually self-limited

Etiology.

Etiology

Varicella-zoster virus (VZV) a neurotropic human herpes virus with similarities to herpes simplex virus also an α-herpesvirus enveloped with double-stranded DNA genomes that encode more than 70 proteins, including proteins that are targets of cellular and humoral immunity

Epidemiology.

Epidemiology

Most children were infected by 15 yr of age, with fewer than 5% of adults remaining susceptible Higher rates of complications and deaths among infants, adults, and immunocompromised personsTransmission of VZV to susceptible individuals occurs at a rate of 65-86%Patients with varicella are contagious from 24-48 hr before the rash appears and until vesicles are crusted, usually 3-7 days after onset of rash

Pathogenesis.

Pathogenesis

Transmitted in respiratory secretions and in the fluid of skin lesions either by airborne spread or through direct contact

Primary infection (varicella) results from the respiratory inoculation of virus

Replicates in the respiratory tract followed by a brief subclinical viremia during the early part of the 10-21-day incubation periodWidespread cutaneous lesions occur during a second viremic phase

Peripheral blood mononuclear cells carry infectious virus, generating new crops of vesicles for 3-7 days

Also transported back to respiratory mucosal sites during the late incubation period, permitting spread to susceptible contacts before the appearance of rash

Establishes latent infection in sensory ganglia cells in all individuals who experience primary infection

Clinical Manifestations.

Clinical Manifestation

Illness - usually begins 14-16 days after exposureIncubation period - can range from 10-21 days24-48 hr before the rash appears: Fever, malaise, anorexia, headache, and occasionally mild abdominal painTemperature elevation - usually moderate, usually from 100-102°F but may be as high as 106° Fever and other systemic symptoms - persist during the first 2-4 days after the onset of the rash

Varicella lesions - often appear first on the scalp, face, or trunk Initial exanthem - consists of intensely pruritic erythematous macules that evolve through the papular stage to form clear, fluid-filled vesicles. Clouding and umbilication of the lesions - begin in 24-48 hr Distribution of the rash - predominantly central or centripetal Ulcerative lesions involving the oropharynx and vagina are also common; many children have vesicular lesions on the eyelids and conjunctivae, but corneal involvement and serious ocular disease is rare

About 300 - average number of varicella lesions Healthy children - may have fewer than 10 to more than 1,500 lesions

Hypopigmentation or hyperpigmentation of lesion sites - persists for days to weeks in some childrenSevere scarring - unusual unless the lesions were secondarily infected

Complications

Bacterial super-infectionPneumoniaEncephalitisBleeding disordersCongenital infectionLife-threatening perinatal infection

TreatmentOral therapy with acyclovir (20 mg/kg/dose; maximum: 800 mg/dose) given as 4 doses per day for 5 days should be used to treat uncomplicated varicella in nonpregnant individuals 13 yr of age or older and children 12 mo of age or older with chronic cutaneous or pulmonary disorders; receiving short-term, intermittent, or aerosolized corticosteroids; receiving long-term salicylate therapy; and possibly second cases in household contacts Intravenous acyclovir (500 mg/m2 q 8 hr IV) therapy initiated within 72 hr of development of initial symptoms decreases the likelihood of progressive varicella and visceral dissemination in high-risk patients. Treatment is continued for 7 days or until no new lesions have appeared for 48 hr

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