Childhood viral exanthems

Roseola Infantum: An Updated Review

BACKGROUND

Roseola infantum is a common viral disease that occurs during childhood worldwide.

OBJECTIVE

The purpose of this article is to familiarize pediatricians with the clinical manifestations, evaluation, diagnosis, and management of roseola infantum.

METHODS

A search was conducted in April, 2022, in PubMed Clinical Queries using the key terms "roseola infantum" OR "exanthem subitum" OR "sixth disease". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Roseola infantum is a viral illness characterized by high fever that lasts 3 to 4 days, followed by the sudden appearance of rash at defervescence. The disease occurs most frequently in children between 6 months and 2 years of age. Human herpesvirus-6 (HHV-6) is the major cause of roseola infantum, followed by HHV-7. Transmission of the infection most likely results from the asymptomatic shedding of the virus in the saliva of the caregivers or other close contacts. Characteristically, the rash is discrete, rose-pink in color, circular or elliptical, macular or maculopapular, measuring 2 to 3 mm in diameter. The eruption is first seen on the trunk. It then spreads to the neck and proximal extremities. Typically, the rash blanches on pressure and subsides in 2 to 4 days without sequelae. Most children look well otherwise and appear to be happy, active, alert, and playful. The diagnosis is mainly clinical. Febrile seizures occur in 10 to 15 % of children with roseola infantum during the febrile period. In general, serious complications are rare and occur more often in individuals who are immunocompromised. There is no specific treatment. An antipyretic may be used to reduce fever and discomfort.

CONCLUSION

Roseola infantum is generally a benign and self-limited disease. Failure to recognize this condition may result in undue parental fear, unnecessary investigations, delay in treatment for conditions that mimic roseola infantum and complications from roseola infantum, unnecessary treatment of roseola infantum per se, and misuse of healthcare expenditure.

Parvovirus B19 in Pregnancy: A Case Review

Parvovirus B19 has been identified as the cause of erythema infectiosum, a common childhood illness. Also known as fifth disease, this virus is highly contagious among school-age children, especially during the winter months when outbreaks within classrooms are widespread. The majority of adults have had the infection in childhood and are immune to recurrence. Approximately 40% of childbearing-age individuals, however, remain nonimmune and susceptible to infection. If acquired during pregnancy, parvovirus B19 infection can have devastating fetal consequences, especially if contracted in the second trimester. Vertical transmission of parvovirus B19 occurs more readily during this gestational period, and fetal loss rates of 8% to 17% have been reported as a result of severe fetal anemia and hydrops fetalis. Unfortunately, adults with parvovirus B19 infection are often asymptomatic and do not exhibit the classic slapped-cheek rash seen in childhood. More commonly, adults will exhibit atypical symptoms such as joint arthralgias. Maternal history of direct exposure to a confirmed case within the family or the presence of atypical symptoms warrants serum antibody screening. Although the presence of immunoglobulin G confirms immunity, any immunoglobulin M positivity will require ongoing fetal surveillance for evidence of fetal anemia and hydrops fetalis. Serial ultrasound imaging for 8 to 12 weeks with Doppler measurements of the peak systolic velocity in the middle cerebral artery are the mainstays of fetal monitoring. Referral to a maternal-fetal medicine specialist with experience in fetal blood sampling and intrauterine transfusion is recommended for any cases of hydrops fetalis or if a concern for severe fetal anemia exists.