Journal of Drugs in Dermatology – The underlying cause of Alzheimer’s disease (AD), a progressive neurologic disorder that is the most common cause of dementia, is poorly understood.

At present, the treatments currently available have limited or questionable benefits and no known preventative treatments exist. 6.5 million Americans over 65 have Alzheimer’s and that number is expected to double by 2050.

In 2021, 239 billion dollars a year was spent by Medicare on dementia and Alzheimer’s, a figure that represents 67% of total Medicare spending. The National Institutes of Health (NIH) spends approximately 3 billion dollars every year on AD research.

The new drug Aduhelm, conditionally approved by the US Food and Drug Agency (FDA) in June 2021, has been met with controversy due to equivocal data regarding its efficacy, significant side effects, and high cost of treatment. Therefore, it may be of benefit to search for therapeutics to treat or prevent Alzheimer’s.

Herpesviridae is a class of viruses that are common causes of mucocutaneous [both typical skin and mucous membrane] pathologies.

“It may be reasonable to treat HSV-1 [herpes] infections using anti-virals to prevent future development of Alzheimer’s.”

The lesions caused by them are often benign and self-resolving and, therefore, immediate treatment is often not requested.

Specifically, Herpes simplex virus 1 (HSV-1) can lead to commonly seen lesions around the oral mucosa and is often left untreated; however, anti-virals such as acyclovir and valacyclovir are frequently administered to manage more severe, acute infections or frequent outbreaks.

The neurotropic nature of HSV-1, as well as its ability to establish dormancy in the sensory root ganglia of the trigeminal nerve, has made it a target of research as a potential infectious etiology for Alzheimer’s.

Various pathophysiologic mechanisms centering around neuroinflammation evoked by the virus in genetically susceptible individuals have been proposed.

Recent studies demonstrate a strong correlation between HSV-1 and AD; however, treatment of HSV-1 for prevention of Alzheimer’s is not currently the standard of care. (continued below … )

Genital Herpes – CDC Basic Fact Sheet

• Oral herpes caused by HSV-1 can spread from the mouth to the genitals through oral sex. This is why some cases of genital herpes are due to HSV-1.
• Genital herpes is common in the United States. In 2018, CDC estimates show there were 572,000 new genital herpes infections in the United States among people aged 14 to 49.1
• You can get genital herpes by having vaginal, anal, or oral sex with someone who has the infection. SOURCE. 

Due to the high prevalence of HSV-1 in the adult population, focusing on HSV-1 anti-viral suppression may be a reasonable course of action considering the possible link to Alzheimer’s in this cohort.

This review includes a literature search investigating epidemiological associations between Alzheimer’s and infection with Herpesviridae, most notably HSV-1, and reports findings and limitations of the reviewed articles.

The included studies take the form of population-based studies of humans. Also, we discuss commonly described pathophysiological mechanisms proposed for this association as well as the clinical relevance for dermatologists. Dermatologists have an important role in AD prevention.

Lastly, we believe that, based on the quality of existing evidence, it may be reasonable to treat HSV-1 infections using anti-virals to prevent future development of Alzheimer’s.

“People who tested positive for the virus behind genital herpes tended to have reduced thickness of their outermost brain layer, which has been linked to Alzheimer’s disease.” – NEW SCIENTIST