ROSEOLA INFANTUM
EXANTHEM SUBITUM Sixth diseaseEpidemiology
caused by human herpesvirus (HHV) type 6 (HHV-6) for<2yrs old 80% of cases; and less frequent in 10-30% of cases by HHV-7 in older than 2 yr. Are DNA viruses, which are of the herpesvirus family HHV-6 is a major cause of acute febrile illnesses in infants and may be responsible for 20% of visits to the emergency department for children 6 to 18 months old.Clinical Manifestations
Roseola is characterized by high fever (often ≥40°C) lasting 3 to 4 days followed by maculopapular, rose-colored pruritic rash that appears soon with the remission of fever. The rash usually lasts 1 to 2 days but may fade rapidly Roseola is associated with approximately one third of febrile seizures cases.Treatment
There is no specific therapy for roseola. Routine supportive care includes maintaining adequate hydration and antipyreticsERYTHEMA INFECTIOSUM FIFTH DISEASE
Epidemiologycaused by the human parvovirus B19 Single stranded DNA virus. Benign self-limited illness affecting any age mostly 5-15 yrs old and even adults . Incubation period average 15-17 days .It is transmitted by respiratory secretions airborne route. it an important cause of aplastic crisis in patients with hemolytic anemias like thalassemia, sickle anemia,& spheroytosis. Parvovirus B19 also causes severe fetal anemia and even hydrops fetalis after primary infection during pregnancy
Clinical Manifestations
usually begin with a mild prodromal nonspecific illness 2-3 days characterized by low grade fever, malaise, myalgia, and headache. This illness is followed by the characteristic rash (Erythema Infectiosum). The rash appears in two stages A. erythematous cheeks, appearing as a "slapped cheek" rashB.After 1-4 days of face rash ; an erythematous symmetric, maculopapular rash, involves trunk and limbs appears, takes place as distinctive lacy, reticulated rash that lasts few days to even 1-3 weeks. This rash may be pruritic, does not desquamate – and it waxes and wanes with exposure to sunlight, heat, bathing, exercise and stress.3.Arthralgia . .
4. anemia due to low RBCs production by bone marrow (suppression) indicated by low RBC count and low reticulocytes count <1% ; which may be mild anemia or may be severe called : acquired pure red cell anemia, and in pregnancy= fetal anemia and even may lead to hydrops fetalis. Investigations includes CBC showing; Low RBC count and; Low Reticulocyte count; and Parvovirus B19 can be detected by PCR .
Treatment
There is no specific therapy. Routine supportive care. Transfusions may be required for ; transient aplastic crisis in pt. with hemolytic diseases or in ; aquired pure red cell anemia. Intrauterine transfusion has been performed for hydrops fetalis associated with fetal parvovirus B19 infection.CHICKENPOX
VARICELLA-ZOSTER VIRUS INFECTIONChickenpox
DNA virus that is a member of the herpes virus family Humans are the only natural host. VZV (chickenpox) is highly communicable among susceptible individuals. It is mild disease in young children but may be severe in adult and in immunocompromised children Both chicken pox( varicella) pt. and pt with zoster lesion (shingles) infect susceptible child leading to chicken pox illness. the period of infectivity to others; ranges from 2 days before to 7 days after the onset of the rash till the time when all lesions are crusted and dried.Epidemiology
the peak age of 5 to 10 yr. peak seasonal infection in late winter and spring Transmission is airborne route by inhalation of the virus in air droplets from pt. sneezing or coughing; also by direct contact with the lesions before it become dried or crusted.Clinical Manifestations
The incubation period of varicella is generally 14 to 16 days Prodromal symptoms ; fever, malaise, and anorexia, running nose may precede the rash by 1 day The characteristic rash appears initially as small red papules that rapidly progress to oval, "teardrop" vesicles on an erythematous base and appears in crops (different lesions) of lesions: papules and vesicles. The fluid progresses from clear to cloudy, and the vesicles then ulcerate, finally; crusted, and dried and heal.New rash appear in 3 to 4 days, usually beginning on the trunk followed by the scalp, the face, conjunctiva, mouth mucosa and, less commonly, the extremities., with all stages of lesions being present at the same time(crops). Pruritus is universal. Periods of illness is about 1-2 weeks . Shingles(herpes zoster) is recurrence of VZV infection in previously infected child.