Observational StudyA Study That Collects Participant Data and Biospecimens to Analyze Pathogenic Exosomes That Mediate Increased Vascular Dementia Risk in Individuals With Herpes Zoster.

Inclusion Criteria:

At the Screening Visit (Visit 1/Day 1), all participants must meet all the following criteria in order to be considered for participation in the study:

1. Be a male or female ≥ 18 years of age.
2. Present to clinic for routine dermatologic evaluation with or without rash.
3. Are willing and able to complete study visits and procedures, and able to effectively communicate with the investigator and other study personnel.
4. Have adequate venous access and are willing to undergo venipuncture for blood draws.
5. Able to provide written informed consent prior to any study procedures. Additional inclusion criteria for Herpes zoster (HZ) participants,
6. Present with acute, vesicle-stage HZ that has not been treated with antiviral therapies
7. Are willing and have reliable transportation to complete additional follow-up visits at 7 days, 1 month, 3 months, 6 months, and 12 months after initial visit for acute HZ.

Exclusion Criteria:

At the Screening Visit (Visit 1/Day 1), participants meeting any of the following criteria will be excluded from participation in the study:

1. Female individuals who are pregnant or breast-feeding.
2. Receiving systemic or topical antivirals for varicella zoster virus (VZV).
3. Sensitivity or allergy to systemic or topical antiviral medications for HZ.
4. History of diagnosed HZ within the last 8 years.
5. Received a HZ vaccine (e.g., Zostavax®/Shingrix®) within the last 8 years.
6. Received any vaccinations within the last 3 months.
7. Currently taking immunosuppressive therapies, including medications and radiation.
8. Currently taking any anticoagulants.
9. History of any coagulation disorder(s).
10. History of end-stage renal disease or uremia.
11. History of end-stage liver disease.
12. History of HIV.
13. Have had a COVID-19 infection in last 3 months.
14. Any history of non-skin cancers within the last 3 months.
15. History of serious infection requiring hospitalization in the last 3 months.
16. Prior history of cardiovascular accident or myocardial infarction within the last 12 months.
17. Prior cerebrovascular accident in the past 12 months.