What is the presentation of Human Herpesvirus 6 (HHV6) viral exanthem?

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From the Guidelines

HHV-6 viral exanthem, also known as roseola infantum or sixth disease, typically presents with a high fever lasting 3-5 days, followed by a distinctive pink rash that appears as the fever breaks, primarily affecting children under two years of age. The presentation of HHV-6 viral exanthem is characterized by:

  • A high fever, often above 102°F, lasting 3-5 days
  • A distinctive pink rash that appears as the fever breaks, usually starting on the trunk and spreading to the neck, face, arms, and legs
  • The rash lasts 1-2 days before fading This information is based on the guidelines for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents, which mentions that HHV-6B causes exanthem subitum (roseola), a common disease of childhood 1. Although more recent guidelines are available, such as the 2019 guidelines from the European Conference on Infections in Leukaemia for management of HHV-6 infection in patients with hematologic malignancies and after hematopoietic stem cell transplantation 1, the key characteristics of HHV-6 viral exanthem presentation remain consistent. Treatment is primarily supportive, focusing on fever management with acetaminophen or ibuprofen at age-appropriate doses, ensuring adequate hydration and rest during the illness. It is essential to note that while HHV-6 viral exanthem is typically mild, parents should seek medical attention if the child appears very ill, has a fever lasting more than 5 days, or shows signs of complications like excessive drowsiness or seizures.

From the Research

Presentation of Human Herpesvirus 6 (HHV6) Viral Exanthem

  • The primary infection with HHV-6 usually presents as exanthem subitum, a common febrile illness in infants 2, 3.
  • Exanthem subitum is characterized by a high fever followed by a rash 2, 4.
  • In some cases, HHV-6 infection can present as febrile disease without an exanthem 4.
  • In adults, an active HHV-6 infection can present as febrile illness, and may also include symptoms such as swelling of the lymph nodes and pancytopenia 4.
  • Reactivation of HHV-6 can occur in immunocompromised patients, and may present with symptoms such as encephalitis, limbic encephalitis, and amnesia 3, 5.

Clinical Features

  • The clinical features of HHV-6 infection can vary depending on the age and immune status of the individual 3, 5.
  • In immunocompetent individuals, HHV-6 infection can cause fulminant hepatitis or meningoencephalitis, which can be severe and require early recognition and treatment 4.
  • In immunocompromised patients, HHV-6 reactivation can cause severe encephalitis, particularly in hematopoietic stem cell transplant recipients 5.

Diagnosis and Treatment

  • The diagnosis of HHV-6 infection is performed by both serologic and direct methods, including the quantification of viral DNA in blood, other body fluids, and organs by means of real-time PCR 5.
  • The antiviral compounds ganciclovir, foscarnet, and cidofovir are effective against active HHV-6 infections, but the indications for treatment and conditions of drug administration are not formally approved to date 5, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Human herpesvirus 6 encephalitis].

Brain and nerve = Shinkei kenkyu no shinpo, 2010

Research

HHV-6 infection - not only tertian fever.

Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG, 2009

Research

Susceptibility of human herpesvirus 6 to antivirals in vitro.

The Journal of infectious diseases, 1990

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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