Identifying Risk Factors for Eczema Herpeticum in Individuals With Atopic Dermatitis

Inclusion Criteria for Participants with AD: * Diagnosis of AD as defined by ADVN standardized diagnostic criteria who fall into one of the following categories: 1. Recurrent, clinically manifested HSV infection with EH 2. Recurrent, clinically manifested HSV infection without EH 3. No recurrent, clinically manifested HSV infection or EH infection Inclusion Criteria for All Participants * Residing in Germany * Good general health other than having an atopic disease * Caucasian * Individuals between 18-60 years of age Exclusion Criteria for All Participants: * Subjects with atopy but lacking stringent AD features, allowing only a presumptive diagnosis of AD * Individuals under 18 or over 60 years of age * Systemic immunosuppressive drugs or chemotherapy 30 days prior to study entry * Oral and topical corticosteroids (including inhaled agents), antibiotics, antivirals, anti-inflammatory biologics (e.g., alefacept, etanercept), topical doxepin, topical coal tar preparations, or topical phosphodiesterase inhibitors 14 days prior to study entry * Immunotherapy * Antibiotics, antivirals, immune enhancers (e.g., imiquimod), or calcineurin inhibitors within 7 days prior to study entry * Phototherapy (e.g., ultraviolet light B \[UVB\], psoralen plus ultraviolet light A \[PUVA\]) 30 days prior to study entry * Cancer, autoimmune diseases, or immunodeficiency * Active fungal, bacterial, or viral infections at screening * Any skin diseases other than AD that might compromise the stratum corneum barrier (e.g., ichthyosis, bullous disease, psoriasis, skin cancer) * Mental illness or a history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements * Inability or unwillingness of a subject to give written informed consent * Weigh less than 40 kg (88.2 lb) * Anxiolytic agents * Antidepressants * Pregnancy or breastfeeding