Systematic review and meta-analysis confirm an association, but not a causal link, between HHV-6 and CFS
So far only one case report has documented HHV-6B reactivation in COVID-19, but the rise in Kawasaki-like symptoms and pityriasis rosea has at least one dermatology group suspicious of HHV-6/7 reactivation.
Patients with DRESS/DIHS hypersensitivity reactions and active HHV-6 often develop autoimmune diseases such as type 1 diabetes and autoimmune thyroiditis. Investigators at National Taiwan University Hospital believe that IP-10 is key to this process.
A group led by Elisabetta Caselli at University of Ferrara discovered HHV-6A in the skin and elevated levels of HHV6-B in the peripheral blood of systemic sclerosis patients
A Swiss team studied 134 young children who were experiencing unidentified high fevers and were able to find at least one virus in 35% of those patients. The two biggest culprits were enterovirus (14%) and HHV-6 (11%).
It has long been a mystery why HHV-6 is preferentially reactivated in drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug induced hypersensitivity syndrome (DIHS). HHV-6 reactivation occurs in over 60% of severe cases and is part of the definition of DIHS in Japan. Investigators in Japan suspect that the explanation may lie with the CD134 receptor on activated CD4 cells.
HHV-6 may be the cause of “fever of unknown origin” in 30% of stem cell transplant (SCT) patients. By the third week after SCT, 70% of HHV-6 positive patients had a skin rash, compared to 39% of HHV-6 negative patients.
Italian study finds 62% of women who developed PR early in their pregnancies miscarried
HHV-6 and other herpesviruses may be involved in the development of acute or recurrent acute urticaria.