Viruses Causing Viruses Causing Maculopapular RashMaculopapular Rash

By:By: Dr. Mona Badr Dr. Mona Badr Assistant Professor & Consultant Virologist

Viruses Causing Maculopapular Viruses Causing Maculopapular RashRash

Definition of Maculopapular Rash:

A small cicumscribed, solid, discoloured spot, slightly elevated lesion on the skin

Some important viruses causing maculopapular rash mainly in children:

1. Measles virus Paramyxvirus family

2. Rubella virus Togavirus family

3. Parvovirus B19 Parvoviridae family

4. Herpes virus type-6 Herpesvirus family

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Measles: Measles is a highly contagious, serious disease affecting young

children mainly and occasionally adults.

A- Virology Aspects:

Family paramyxoviridae

Enveloped virus

ss-RNA, negative polarity

Virion contain enzyme transcriptase

Paramyxovirus are able to induce cell-cell fusionmultinucleated giant cell (syncytia)

Measles virus -One serotype only

- Infect human only

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B- Pathogenesis and Immunity:

Measles virus transmitted from respiratory secretion by direct contact OR droplet and air borne transmission mainly in winter and spring.

Virus infects first epithelial cells of respiratory tract, then virus spreads in lymphatic system blood then measles viruses wildly disseminated to the skin and other internal organs.

Cell-mediated immunity is essential for the control of measles infection will be fatal in immunocompromised.

Long-life immunity to measles virus develop after recovery from rash.

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C- Clinical Symptoms:

Incubation period 7-13 days

Prodromal symptoms: Fever, cough, runny nose, conjunctivitis, (1-2 days).

Koplik’s spot: Small, white papules appear mostly in buccal mucosa, of 70-80% of patients for 2 days

Rash: typical maculopapular rash first on the face, trunk and extremities.

The patient become very sick and temperature become very high (39-40oC) when this rash appear.

Recovery can be complete, but complication also can occur.

Diagnosed by detection of Measles IgMAb in the serum.

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D- Complication:

Common complication

bronchitis, otitis media and 2nd bacterial pneumonia

Rare Complication:

1. Encephalitis occur in 1 per 1000 of infected children.

Occur 7-10 days after the onset of measles,its serious its fatal.

2. Giant cell pneumonia (Intestinal pneumonia)

Occur in immunocompromised children, due to direct invasion of the virus to lung.

Koplik”s SpotKoplik”s Spot

MeaslesMeasles

MeaslesMeasles

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D- Complication:

Very rare Complication:

Subacut-slerosing-pan-encephalitis (SSPE)

Is very rare complication (5/million)

Develops several month or years after recovery average after 7 years.

It occur when measles virus persist in brain tissue and act as slow virus and replicate in brain cells.

Patients develops change in personality, behavior, memory blindness and convulsion will lead to coma then death.

SSPE is confirmed by characteristic EEG patterns and demonstration of measles Ab in CSF with increased CSF measles Ab ratio to serum measles Ab.

No effective treatment .

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E- Treatment and Prevention

No specific treatment

Prevention

1. Active Live attenuated vaccine (MMR)

Contain live attenuated measles, mumps and rubella viruses

Given by I.M. or subcutaneously in one dose.

Excellent immunity

Should not be given to pregnant or immunocompromised patient.

2. Passive

Exposed people who are immunocompromised should be given passive immunization with immune serum globulin must be given within 6 days of exposure.

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Rubella

Rubella is a mild exanthematous moderately contagious disease. When the disease is acquired by the mother during first 4 months of pregnancy. The virus may infect the fetus and cause malformation.

1. Virology Aspects: Family Togavirus

Enveloped, nucleocapsid virus

Single stranded RNA, positive polarity

Agglutinate avian erythrocytes

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2. Epidemiology:

Humans are the only host for rubella

Virus is spread in respiratory secretion and is generally acquired during childhood.

The incidence of infection peaks in the spring

Before the development and use of the rubella vaccine, cases of rubella in school children would be reported evey spring.

3- Clinical Syndromes:

Rubella is a mild disease of children

But if contracted in early pregnancy (first 4 months) the virus can cause severe congenital abnormalities in the fetus (Teratogenic)

So we have 2 different

Clinical Syndrome

Post –natal

Rubella Infection

Congenital

Rubella Infection

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A- Post –natal Rubella

It is mild self limiting disease occur in childhood.

Incubation period 14-21 days

Prodromal symptoms as fever, cough, conjunctivitis and enlarged of post cervical lymph node.

Macupapular rash first appear in face then trunk and limbs (usually mild), with complete recovery.

Fever is low grade or absent during the rash. The general condition is good.

If infection occur in adult (especially female) arthritis reported.

Diagnosed by detection Rubella IgM Ab in the serum

Complication: Post – infectious encephalitis Thrombocytopenic purpura

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A- Congenital Rubella

Congenital defect occur mainly if the mother has rubella in the first 16 weeks of pregnancy (first trimester), after that rubella does not damage the fetus.

Virus can replicate in the placenta and then spread to fetal blood supply and so, Rubella virus can replicate in most tissue of the fetus, this can lead to improper development of the fetus and teratogenic effect associate with Congenital Rubella infections.

In about 15% of cases infection of the fetus leads to spontaneous abortion.

Congenital Rubella Congenital Rubella

Viruses Causing Maculopapular RashViruses Causing Maculopapular Rash (Continued) (Continued) The main defects are:

Eye defect: cataract, glucoma, chorioretenitis

Nerve deafness

Cardiac abnormalities:

e.g.: Fallot’s tetralogy

Ventricular septal defect.

Mental retardation

Hepatosplenomegally

Low birth weight

Notes: Infected infants shed the virus into throat and urine for 2 years and can infect susceptible individual.

5- Laboratory Diagnosis

Post –natal Rubella

Congenital Rubella

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1- Clinical diagnosis

2- Serological detection of IgM Ab

3- Detection of IgG Ab indicate

past infection OR immunization.

1- History of Infection of mother

2- Virus isolated by immuno-

flourescent assay from:UrineCSFBlood

3- Serological diagnosis by

detection of IgM Ab from Cord blood

4- Detection of IgG Ab Not diagnostic

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Treatment and Prevention:

No specific treatment available.

Prevention:

Active Immunization:

Immunization of all children at age of 15 months with MMR-vaccine (live attenuated vaccine).

Natural infection or vaccination give good immunity, but not solid, re-infection can happen.

Booster, dose of Rubella vaccine is recommended for female at age of puberty (14-15 years), or before marriage.

Contraindication of MMR:

Pregnancy: must be avoided 1-3 months after vaccination

Immunodeficiency patient

Hypersensitivity to egg.

3- PARVO-VIRUS B19Erythema Infectiosum Fifth disease

Parvovirus B19 replicates in erythroid cells of human bone marrow or erythroid cells of fetal liver.

Parvovirus B19 is cytocytic for erythroid cells cause severe fall of Hb due to transient aplastic anemia especially in patient with chronic haemolytic disorder.

1. Virology Aspects

Family parvovirus

The smallest DNA virus

The only DNA virus with ssDNA

Un-enveloped virus

Only one serotype, infect only human.

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2- Clinical Syndromes

Parvovirus in normal child

The common form of the disease Fifth disease or “Slapped Cheek”, Erythema infectiosum.

Is childhood disease, transmitted from child to child by respiratory droplets with I.P: 4 10 days, symptoms started

as fever, sore throat, malaise, with decrease Hb. Due to transient arrest of erythropoiesis.

Then followed by rash on the cheeks that look like person

has been slapped, then rash spread to trunk and limbs with complete recovery within one week.

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Parvovirus B19 “Slapped Cheek”Parvovirus B19 “Slapped Cheek”

Erythema Infectiosum

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Parvovirus B19 in patient with chronic hemolytic anemia:

Infection in these group of patient e.g. sickle cell anemia, thalassemia can lead to severe aplastic crisis which can be fatal.

Parvovirus B19 in adult:

Usually can lead to polyarthritis without appearing of rash especially in adult female.

Parvovirus B19 in pregnant lady:

The virus can infect the fetus and kill erythrocyte precursors, causing anemia, and congestive heart failure hydrops fetalis.

But No congenital abnormalities Not Teratogenic

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Laboratory Diagnosis:

Detection of IgM Ab.

Treatment and Prevention:

No specific treatment

No way of prevention except we can screen the blood before transfusion especially if we give it to chronic heamolytic patient.

4- HERPES VIRUS TYPE 6 Roseola infantum Sixth disease

Exanthema subitum

1. Virology Aspects

Herpes virus type 6- Family Herpes virus

Double stranded DNA. Enveloped virus.

Has the characteristic of latency.

latent virus persists for long period to be activated when immunity become less.

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2- Clinical Syndromes:

It is mainly a childhood disease

It is transmitted by respiratory droplet

Rapid onset of high fever, followed by generalized rash, with mild lymphadenopathy.

Complete recovery after 3-5 days.

3- Treatment and Prevention

No specific way of treatment or prevention

No vaccine available

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