Atopic Dermatitis (AD) and Food Allergy

Atopic Dermatitis (AD) is a chronic inflammatory skin disorder in which the skin becomes
extremely itchy and is susceptible to recurrent skin infections. AD is thought to occur from
a combination of immunological, genetic, and environmental factors.

Those with atopic dermatitis (AD) often have food allergy and Staphylococcus aureus (S.
aureus) colonization of the skin. There is evidence suggesting that skin barrier dysfunction,
measurable as increased transepidermal water loss (TEWL), is a predisposing factor to food
sensitization and food allergy from epicutaneous penetration of environmental food allergens.
Furthermore, the investigators for this study have identified that AD children with food
allergy, especially peanut allergy, are colonized with Staphylococcus aureus. However, only
half (50%) of children with AD have food allergy or S. aureus colonization, suggesting there
are other factors accounting for food allergy. There have been no previous studies of TEWL
or, microbial or molecular profiling of the skin in those with AD prone to food allergy
versus AD without food allergy.

Inclusion Criteria:

Participants fulfilling all of the following criteria are eligible for enrollment-

-Parent/guardian must be able to understand and provide informed consent and participant
provide assent as applicable per Institutional Review Board (IRB) guidelines and
regulations;

For Eligibility to One of the Two Active Atopic Dermatitis (AD) Groups:

-Active Atopic Dermatitis (AD) without a history or current manifestations of eczema
herpeticum (EH), as diagnosed using the Atopic Dermatitis Registry

Network (ADRN) Standard Diagnostic Criteria and food allergy to peanut. Participant must
meet all of the following criteria:

- Self-report or documentation of a positive oral food challenge to peanut or
self-report of an allergic reaction to peanut within 2 hours of ingestion

- Peanut skin prick test wheal ≥ 8 mm. OR -Active AD without a history or current
manifestations of EH, as diagnosed using ADRN Standard Diagnostic Criteria and no food
allergy.

Participant must meet all of the following criteria:

- No personal history or current manifestations of food allergy (based on no self-report
of a positive oral food challenge, positive skin test, positive blood test, or
allergic reactions).

- Negative skin prick test (wheal < 3 mm) to peanut, milk, egg, wheat, soy, shellfish
mix, tree nuts, and sesame seed.

For Non-atopic (NA) Group Eligibility:

Participant must meet all of the following criteria:

- No personal history or current manifestations of AD, asthma, or allergic rhinitis
(based on self-report);

- No personal history or current manifestations of food allergy (based on no self-
report of a positive oral food challenge, positive skin test, positive blood test, or
allergic reactions);

- Negative skin prick test (wheal < 3 mm) to peanut, milk, egg, wheat, soy, shellfish
mix, tree nuts, and sesame seed; and

- Negative skin prick test (wheal < 3 mm) to environmental allergens (cat, dog, dust
mite, cockroach, and local trees/grasses/weeds/molds).

Exclusion Criteria:

- Inability or unwillingness of a parent/guardian to give written informed consent, or
participant to give assent, if applicable, or to comply with study protocol;

- Subjects with skin disease other than AD that might compromise the stratum corneum
barrier (e.g., bullous diseases, psoriasis, cutaneous T cell lymphoma [also called
Mycosis Fungoides or Sezary syndrome], dermatitis herpetiformis, Hailey- Hailey, or
Darier's disease);

- Pregnant or lactating females;

- Known or suspected immunosuppression;

- Severe concomitant illness(es);

- History of serious life-threatening reaction to latex, tape, or adhesives;

- 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;

- Use of biologics within 5 half-lives (if known) or 16 weeks of the Screening Visit;

- Use of an investigational drug within 5 half-lives (if known) or 8 weeks of the
Screening Visit; or

- Has received immunotherapy within 12 months of the Screening Visit.