Common Pediatrics Infectious Diseases

Is a widespread rashIs a widespread rash, usually viralIs a widespread rash, usually viral, and usually occurring in children.
It represents either a reaction to a toxin It represents either a reaction to a toxin produced by the organism damage to the skin It represents either a reaction to a toxin produced by the organism damage to the skin by the organism an immune response. or due to a drug, most commonly antibiotics.
Exanthems

Exanthema
Measles.
Rubella.
Scarlet fever
Chicken pox.
Erythema infectiosum.
Roseola infantum.

Historically, exanthems in children have been numbered in the order they were identified:
First disease - RubeolaFirst disease - Rubeola, MeaslesFirst disease - Rubeola, Measles (caused by Morbillivirus)
Second disease -rubella, German measles caused rubella virus)
Third disease -,scarlet fever,scarlatina,caused by Group A strep- the only bacterial exanthem.
Fourth disease- varicella –chicken pox- hepes zoster
Fifth disease Erythema infectiosum caused by parvo virus B19
Sixth disease Roseola infantum. Caused by human herpes virus simplex 6

Measles

Measles
Measles, also known as rubeola, is a disease, is a disease caused by a virus, is a disease caused by a virus, specifically a paramyxovirus of the genus Morbillivirus.
Measles is spread through respiration (contact with fluidsMeasles is spread through respiration (contact with fluids from an infectedMeasles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious.
The incubation period The incubation period usually lasts for 10-12 days (during which there are no symptoms).
Infected people remain contagious from the appearance of the first symptoms until 3-5 days after the rash appears.

Symptoms
fever for at least three days, 40° Celsius.
Three Cs—coughs—cough, coryzas—cough, coryza (runny nose) conjunctivitis (red eyes)
Koplik's spots seen inside the mouth are pathognomonic transient and may disappear within a day of arising.
Maculopapular, erythematous, erythematous rash that begins several days after the fever starts. It starts on the head before spreading to cover most of the body. The measles rash also classically "stains" by changing colour from red to dark brown before disappearing later. The rash can be itchy.

DIAGNOSIS
A detailed history. vaccination history, contact history, and travel history.
Clinical diagnosis of measles requires a history of fever of at least three days together with at least one of the three Cs.
Observation of Koplik's spots is also diagnostic of measles.
Laboratory diagnosis of measles can be done with confirmation of positive measles IgM antibodies or isolation of measles virus RNA from respiratory specimens.
Positive contact with other patients known to have measles adds strong epidemiological evidence to the diagnosis.

Measles
Measles

TREATMENT
No specific therapy for measles .
Adequate hydration and antipyretics.
Avoid strong light :photophobia.
IV ribavirin in severe cases.
High dose vit A supplementation for 6M to 2 years old need hospitilization ,HIV-infected infants,and infant in endemic areas in devoloping countries.

Complications
Otitis media.the most common
Interstitial pneumonia.
giant cell pneumonia.
Activate latent T.B.
Myocarditis ,and mesentric lymphadenopathy.
Encephalomyelitis.
Subacute scelorosing panencephlitis.

Prognosis
Death due to bronchopneumonia or encephlitis,and subacute scelorosing panencephlitis.
Mortality rate is 15%with 20% to 30% of survivor having serious neurological sequele.
Prevented by vaccine.

Prevention & vaccination
MMR vaccine
first dose 12 to 15 months of age.
second dose at school entry
People who have measles should limit their contact with others.
Exposure
within 3 days ------ vaccine
within 6 days ------ immunoglobin

Rubella
German measles
Three days measles

Rubella
( German Measles )
Rubella is also called as 3 day Measles or German Measles.
Family – Togaviridae
Genus - Rubivirus
In general belong to Togavirus group

Rubella Virus
Rubella virus are
ss – RNA virus
Diameter 50 – 70 nm
Enveloped Spherical
Virus carry hemagglutinin
Virus multiply in the cytoplasam of infected cell.

Clinical findings
Malaise
Low grade fever
Morbilliform rash
Rash starts on Face Extremities
Rarely lasts more than 5 days
No features of the rash give clues to definitive diagnosis of Rubella.

Systemic events of Rubella Infection

Adults and children:
swollen glands or lymph nodes (may persist for up to a week)
fever (rarely rises above 38 degrees Celsius
rash (Appears on the face and then spreads to the trunk and limbs. It appears as pink dots under the skin. It appears on the first or third day of the illness but it disappears after a few days with no staining or peeling of the skin)
Forchheimer's signForchheimer's sign occurs in 20% of cases, and is characterized by small, red papulesForchheimer's sign occurs in 20% of cases, and is characterized by small, red papules on the area of the soft palate
cojunctivities

Other manifestations and complications
May produce transient Arthritis, in women in particular.
Serious complications are
Thrombocytopenia
Purpura
Encephalits

Classical Triad of Rubella
Classical Triad
Cataract
Cardiac abnormalities
Deafness
Other manifestations
Growth retardation Rash
Hepatosplenomegaly
Jaundice
Meingoencephalitis
CNS defects lead to moderate to profound mental retardation

Diagnosis of
Congenital Rubella Syndrome
Demonstration of Rubella antibodies of IgM in a new born is diagnostic value. As IgM group donot cross the placenta and they are produce in the infected fetus,

Immunity - Rubella
Antibodies appear in serum as rash fades and antibody titers raise
Rapid raise in 1 – 3 weeks
Rash in association with detection of IgM indicates recent infection.
IgG antibodies persist for life

Immunity - Protects
One attack of Rubella infection, protects for life
Immune mothers transfer antibodies to off springs who are in turn are protected for 4 – 6 months.

Treatment, Prevention, Control
No specific treatment is available
CRS can be prevented by effective immunization of the young children and teenage girls, remain the best option to prevent Congenital Rubella Syndrome.
The component of Rubella in MMR vaccine protects the vaccinated

MMR Vaccine
The MMR vaccine is a mixture of three live attenuated viruses is a mixture of three live attenuated viruses, administered via injection for immunization is a mixture of three live attenuated viruses, administered via injection for immunization against measles is a mixture of three live attenuated viruses, administered via injection for immunization against measles, mumps is a mixture of three live attenuated viruses, administered via injection for immunization against measles, mumps and rubella is a mixture of three live attenuated viruses, administered via injection for immunization against measles, mumps and rubella. It is generally administered to children around the age of one year, with a second dose before starting school (i.e. age 4/5). The second dose is not a booster; it is a dose to produce immunity in the small number of persons (2-5%) who fail to develop measles immunity after the first dose In the United States, the vaccine was licensed in 1963 and the second dose was introduced in the mid 1990s. It is widely used in all National, Universal Immunization programmes

Chickenpox-varicella

Etiology
Chickenpox and zoster are caused by varicella -zoster virus .
(VZV) ,an enveloped ,double stranded DNA virus that is a member of the herpes virus family.
Human are the only natural host.

Etiology cont…
After resolution of chickenpox,the virus persists in latent phase in the dorsal root ganglia cell.
Its highly communicable with secondary attack rate of more than 90%.

The Stages of Chickenpox
Incubation Period
Usually (14-17 days)
Prodrome (1 – 3 days)
Vesicles
Pustules
Scabs
Recovery typically 7 days after
rash appears (ranges 5 - 35 days)

Clinical Features
Mild prodrome (fever, malaise) for 1-2 days
Successive crops (2-4 days) of pruritic vesicles
Generally appear first on head; most concentrated on trunk
Can spread over the entire body causing between 250 to 500 itchy blisters
Generally mild in healthy children

NEONATAL CHICKENPOX.
Birth within 1 wk before or after the onset of maternal varicella frequently results in the newborn developing varicella, which may be severe.
The initial infection is intrauterine, although the newborn often develops clinical chickenpox postpartum.
The risk to the newborn is dependent on the amount of maternal anti-VZV antibody that the fetus acquired transplacentally before birth.

Damage to Sensory Nerves. Cicatricial skin lesions
Hypopigmentation.Damage to Optic Stalk and Lens Vesicle.Microphthalmia.Cataracts.Chorioretinitis.optic atrophy.Damage to Brain/Encephalitis,Microcephaly.Hydrocephaly
Calcifications.Aplasia of brain
Damage to Cervical or Lumbosacral Cord
Hypoplasia of an extremity.Motor and sensory deficits
Absent deep tendon reflexes.Anisocoria.Horner syndrome,Anal/urinary sphincter dysfunction
Stigmata of Varicella-Zoster Virus Fetopathy:

Herpes Zoster (Shingles)
Reactivation of Varicella Zoster Virus
Associated with:
Aging
Immunosuppression
Intrauterine exposure
Varicella at <18 month of age

Groups at Increased Risk of Complications
Normal Adults
Immunocompromised persons
Newborns with maternal rash onset within 5 days before to 48 hours after delivery

Can you get chickenpox more than once?
Yes
But it is uncommon to do so.
For most people, one infection is thought to confer lifelong immunity.

What Complications Result From Varicella?
The most common complications are:
Bacterial infections of the skin and soft tissues in children
Septicemia
Toxic Shock Syndrome
Necrotizing Fascitis
Osteomyelitis
Bacterial pneumonia
Septic arthritis.

What home treatments are available for chickenpox?
Fingernails trimmed short
Calamine lotion and Aveeno (oatmeal) baths may help relieve some of the itching
Aspirin or aspirin-containing products to relieve your child's fever are not recommended.
The use of aspirin has been associated with development of Reye syndrome (a severe disease affecting all organs - most seriously affecting the liver and brain, that may cause death).
The use of non aspirin medications such as acetaminophen is recommended.

Varicella Vaccine Recommendations
Routine vaccination at 12 to 18 months of age
Recommended for all susceptible children by the 13th birthday
Persons >13 years of age without history of Varicella
Two doses separated by 4 – 8 weeks

Zoster Following Vaccination
Most cases in children
Risk from wild virus 4 to 5 times higher than from vaccine virus
Mild illness without complications

Varicella Zoster Immune Globulin (VZIG)
May modify or prevent disease if given <96 hours after exposure
Indications:
Immunocompromised persons
Newborn of mothers with onset 5 days before to 2 days after birth
Premature infants with postnatal exposure
Susceptible adults and pregnant women

Erythema infectiosum
fifth disease

Erythema infectiosum fifth disease:
Caused by human parvovirus B19.
In children between three and 12 years of age, although it can present as a rheumatic syndrome in adults.
The prodrome : fever, anorexia, sore throat and abdominal pain.
Once the fever resolves, the classic bright-red facial rash (“slapped cheek”) appears.
Exanthem progresses to a diffuse, lacy, reticular rash that may wax and wane for six to eight weeks .

Erythema infectiosum

The incubation period is usually 7-10 days but can be 4-21 days.
The mechanism producing the dermatologic and rheumatologic features is unknown but thought to represent antigen-antibody (Ag-Ab) complexes in the skin and joints.
Arthropathy is observed most commonly in adult women and occurs in fewer than 10% of children. It is a symmetric polyarthritis, usually involving finger joints. The onset of joint symptoms occurs 2-3 weeks after exposure

Roseola infantum

Background
Roseola infantum is the sixth of the traditional exanthems of childhood.
The condition is an acute benign disease of childhood characterized by a history of a prodromal febrile illness lasting approximately 3 days, followed by the appearance of a faint pink maculopapular rash.

Causes:
HHV-6 was identified as the etiologic agent in 1988.
This large, double-stranded (DNA) virus is a member of the Herpesviridae family.
The incubation period
is approximately 9 days (range, 5-15 d).

Mortality/Morbidity:
Roseola is usually a self-limited illness with no sequelae.
The major morbidity associated with roseola is seizures (6-15%) during the febrile phase of the illness.
Encephalitis, fulminant hepatitis, and disseminated infection with HHV-6 are extremely rare manifestations.

History:
Most cases present within the first 2 years of life, with peak occurrence in infants aged 9m-2y
Roseola is typically characterized by a history of high fever followed by characteristic rash.
Fever (often up to 40°C)
Rash (fades within a few hours to 2 d)
Maculopapular or erythematous
Typically beginning on the trunk and may spread to involve the neck and extremities
Nonpruritic
Blanches on pressure

Medication :
To date, no controlled antiviral trials exist against HHV-6..
Prevention : Because of the ubiquity of the virus, isolation of patients with HHV-6 infection is probably unnecessary

Scarlet Fever

Scarlet fever
Is an exotoxinIs an exotoxin-mediated disease caused by Group A streptococcal infectionIs an exotoxin-mediated disease caused by Group A streptococcal infection that occurs most often in association with a sore throat and rarely with impetigo or other streptococcal infections.
Scarlet fever is not rheumatic fever rheumatic fever. Rheumatic fever is the autoimmune disease that occurs after infection with Group A strep that causes damage to the heart valves.
The disease was once greatly feared and killed many thousands of people. Today, however, it is fairly easy to treat with modern antibiotics.

Clinical manifestation
Scarlet fever generally has a 1- to 4-days incubation period.
Emergence of the illness tends to be abrupt, usually manifested by sudden onset of fever associated with sore throat, headache, nausea, vomiting, abdominal pain, myalgias, and malaise.
The characteristic rash appears 12-48 hours after onset of fever.
In the untreated patient, fever peaks by the second day (as high as 103-104°F) and gradually returns to normal in 5-7 days.
Fever abates within 12-24 hours after initiation of antibiotic therapy.

Skin rash scarlatina
generally starts on the chest, axilla , and behind the ears
worse in the skin folds
Pastia linesPastia lines (small linear petechiae) appear and persist after the rash is gone
Scarlet fever also produces a bright red tongue with a "strawberry" appearance.
The area around the mouth is usually pale (circumoral pallor)
After about a week, the skin often desquamates or peels, usually in the groin, axilla, and on tips of fingers and toes

Complications
arise from suppurative complications such as;
*peritonsillar abscess,
*sinusitis,
*bronchopneumonia,
*and meningitis, or problems associated with immune system as rheumatic fever or
glomerulonephritis

Desquamation, one of the most distinctive features of scarlet fever, begins 7-10 days after resolution of the rash and may continue up to 6 weeks.

Lab Studies:
1. Throat culture remains the “gold standard” for confirmation of group A streptococcal upper respiratory infection.
ASOT
antistreptolysine o titere

treatment
penicillin
Pediatric Dose
<12 year: 25-50 mg/kg/d PO divided tid/qid; not to exceed 3 g/d
>12 year: Administer as in adults
Adult Dose 250 mg PO tid/qid for 10 d
Contraindications Documented hypersensitivity

TOXIC SHOCK SYNDROME AND SCALDED SKIN SYNDROME
Staphylococcus aureus exotoxins responsible for classic toxic shock syndrome and scalded skin syndrome.
Presention : hypotension, erythema, fever and multisystem dysfunction.
The rash : diffuse and can present as bullous impetigo, scarlatiniform lesions or diffuse erythema.
The mucous membranes :spared

Coxsackie viruses and other enteroviruses
Hand-foot-and-mouth disease: the children develop fever and rash. The rash includes blisters to the mouth and tongue, to the hands and the feet.
Herpangina causes a fever, sore throat, and painful blisters or ulcers to the back of the mouth.

Hand-Foot-Mouth Disease
Enteroviruses
coxsackieviruses A and B
echoviruses
Vesicular lesions, may be petechial
Associated with aseptic meningitis, myocarditis

Infectious Mononucleosis
Acute, self limited illness
Epstein-Barr virus
Oral transmission – incubation 30-50 days
Fever, fatigue, pharyngitis, LA, splenomegaly, atypical lymphocytosis
Exanthem is seen in 10-15%
Erythematous, maculopapular, morbilliform, scarlatiniform, urticarial, hemorrhagic, or even nodular

Impetigo
Superficial infection of the dermis
Two types:
Impetigo contagiosa
Bullous impetigo
Etiology
Group A ß hemolytic streptococcus
Coagulase positive S. aureus
Treatment : Keflex, erythromycin, Bactroban

Rocky Mountain Spotted Fever
Most common rickettsial infection in US
Abrupt fever, headache, and myalgia
Rash from extremities towards trunk
Macules→petechiae
Treatment
Tetracycline
Doxycycline
Chloramphenicol

Periorbital- Orbital Cellulitis
S. aureus, S. pneumoniae, and HIB
CBC, blood culture, CT
LP?
IV antibiotics
Admit

Kawasaki Syndrome
Unknown etiology
Peak incidence 18-24 months
Clinical findings:
Fever for at least five days
Conjunctivitis
Polymorphous rash
Oral cavity changes
Cervical adenopathy

Erythema Toxicum Neonatorum
Impressive title - harmless skin condition
Erythematous macule with a central tiny papule, seen anywhere - except the palms and soles.
The lesions are packed with eosinophils, and there may be accompanying eosinophilia in the blood count.
The cause is unknown, and no treatment is required as the rash disappears after 1-2 weeks.

Miliaria
Prickly heat, sweat rash
Many red macules with central papules, vesicles or pustules are present.
These may be on the trunk, diaper area, head or neck.

Infantile Atopic Dermatitis
Cause is unknown
Red, itchy papules and plaques that ooze and crust
Sites of Predilection
Face in the young
Extensor surfaces of the arms and legs 8-10 mo.
Antecubital and popliteal fossa , neck, face in older

Eczema- Treatment
Avoidance or elimination of predisposing factors
Hydration and lubrication of dry skin
Anti-pruritic agents
Topical steroids

Seborrheic Dermatitis
Common, generally self-limiting
Its cause remains ill-understood
There is a genetic predisposition
Most frequent between the ages of 1 to 6 mo.
Greasy, salmon-colored scaling eruption
Hair-bearing and intertriginous areas
The rash causes no discomfort or itching

Seborrheic Dermatitis-Treatment
Anti-seborrheic shampoo
Topical steroids

Cytomegalovirus (CMV)
Most common congenital viral infection
~40,000 infants per year in the U.S.
Mild, self limiting illness
Transmission can occur with primary infection or reactivation of virus
40% risk of transmission in primary infxn
Studies suggest increased risk of transmission later in pregnancy
However, more severe sequalae associated with earlier acquisition

Clinical Manifestations
90% are asymptomatic at birth!
Up to 15% develop symptoms later, notably sensorineural hearing loss
Symptomatic infection
SGA, HSM, petechiae, jaundice, chorioretinitis, periventricular calcifications, neurological deficits
>80% develop long term complications
Hearing loss, vision impairment, developmental delay

Ventriculomegaly and calcifications of congenital CMV

Diagnosis
Maternal IgG shows only past infection
Infection common – this is useless
Viral isolation from urine or saliva in 1st 3weeks of life
Afterwards may represent post-natal infection
Viral load and DNA copies can be assessed by PCR
Less useful for diagnosis, but helps in following viral activity in patient
Serologies not helpful given high antibody in population