Atopic dermatitis, also called eczema, is a disease with dry, scaly, itchy skin. Those with atopic dermatitis may have complications from skin infections such as eczema herpeticum after herpes simplex virus (HSV) infection. Symptoms of eczema herpeticum include fever and clusters of itchy blisters which crust over and form sores. Although exposure to HSV is widespread, most people clear the virus and only a subset of individuals with atopic dermatitis develop eczema herpeticum.

The purpose of this study is to determine why some individuals with atopic dermatitis are at higher risk for recurrent skin infections with HSV. The study team will compare how people with atopic dermatitis with a history of recurrent eczema herpeticum, people with atopic dermatitis without a history of eczema herpeticum, and people without atopic dermatitis respond to HSV.

This study uses whole genome sequencing (WGS) technology to identify genetic variants that confer risk of recurrent atopic dermatitis with a history of eczema herpeticum (ADEH+), with ≥3 eczema herpeticum (EH) episodes.

A small subgroup of individuals with atopic dermatitis (AD) suffer from life-threatening disseminated herpes simplex virus (HSV) skin infections, termed eczema herpeticum (ADEH+). The manifestation of ADEH+ however is not simply a consequence of herpes simplex virus type 1 (HSV-1) infections, since the majority of the US population is latently infected with HSV-1 from an early age. Most importantly, there is a bimodality in the recurrence of eczema herpeticum (EH) episodes; most individuals have only a single episode but a subgroup of ADEH+ individuals has 3 or more episodes.

This study aims to conduct an extreme trait investigation of ADEH+ with recurrent EH, ≥3 episodes, compared to AD without a history of eczema herpeticum (ADEH-), using whole genome sequencing.

Inclusion Criteria:

1. Must be a participant already enrolled in the ADRN Registry and provided DNA (ClinicalTrials.gov ID: NCT01494142);

2. Participant and/or parent guardian must be able to understand and provide informed consent;

3. A history of Atopic Dermatitis (AD) with a history of eczema herpeticum (ADEH+), as diagnosed using the Atopic Dermatitis Research Network (ADRN) Standard Diagnostic Criteria, with ≥3 episodes of Eczema Herpeticum (EH)

   OR

   A history of AD without a history of eczema herpeticum (ADEH-), as diagnosed using the ADRN Standard Diagnostic Criteria, and no immediate family members (mother, father, full siblings, half-siblings, offspring, aunts, uncles, cousins, or grandparents) with a history of EH

   OR

   Non-atopic as diagnosed using the ADRN Standard Diagnostic Criteria.

4. Anti-Herpes Simplex Virus (HSV)-1 or Anti-HSV-2 Immunoglobulin G (IgG) seropositive.

Exclusion Criteria:

1. Inability or unwillingness of a participant and/or parent guardian to give written informed consent or comply with study protocol;
2. Pregnant or lactating women;
3. Known or suspected immunosuppression;
4. Severe concomitant illness(es);
5. History of keloid formation (adults only);
6. History of lidocaine or Novocain allergy (adults only);
7. History of serious life-threatening reaction to latex, tape, or adhesives;
8. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.
9. Use of biologics within 5 half-lives (if known) or 16 weeks of the Screening Visit;
10. Use of an investigational drug within 5 half-lives (if known) or 8 weeks of the Screening Visit.

A minimum of 50 recurrent Atopic Dermatitis with a history of Eczema Herpeticum(ADEH+), 500 Atopic Dermatitis without a history of Eczema Herpeticum (ADEH-), and 237 Non-Atopic (NA) European American participants from the Atopic Dermatitis Research Network (ADRN) DNA Repository. The protocol will also enroll two independent populations of participants 1) children, 3-17 years of age and 2) adults 18-64 years of age. A minimum of 12 recurrent ADEH+ with ≥3 EH episodes, 12 ADEH- and 12 NA participants will be enrolled in each of the two populations.