Inclusion Criteria:

• * 18 - 50 years old
• * Participant must be able to understand and perform informed consent.
• * IgE-mediated food allergy to at least one of the following foods as defined by (regarding at least one of the foods):
• ° Foods: peanut, cashew, walnut, hazelnut, sesame, cod, and/or shrimp, history of an acute allergic reaction (urticaria, angioedema, cough, wheeze, and/or repetitive vomiting within an hour of ingestion, and history of positive skin or serum IgE test, and current strict avoidance of the food, and current possession of physician-prescribed self-injectable epinephrine, and skin test wheal 5 mm or greater average diameter
• * Current or past eczema.
• * If female of childbearing potential, must have a negative pregnancy test (serum or urine) and agree to abstinence or acceptable contraception.
• * Plan to remain in the Tri-State area during the trial for visits.
• * Must agree to avoid prolonged exposure to the sun and not to use tanning booths, sunlamps, or other ultraviolet (UV) light sources during the study.
• * If receiving concomitant medications for any reason other than AD, must be on a stable regimen, which is defined as not starting a new drug or changing dosage within 7 days or 5 half-lives (whichever is longer) prior to Day 1 and through the duration of the study.

Exclusion Criteria:

• * Unwilling or unable to give written informed consent or comply with protocol.
• * Unable to swallow pill.
• * Use of dupilumab within 6 weeks of enrollment.
• * Prior use or allergy to drugs related to abrocitinib (ruxolitinib, upadacitinib, etc).
• * Use of any other biologic (monoclonal antibody) medication within 12 weeks or 5 half-lives of drug, if known.
• * Allergy to any excipients within abrocitinib.
• * Use of build-up environmental immunotherapy; any food oral immunotherapy;or systemic oral, IV or IM steroids including but not limited to- prednisone, methylprednisolone, prednisolone, solumedrol, solucortef, dexamethasone in the past 4 weeks or 5 half-lives of drug, if known.
• * Use of CYP2C9 and CYP2C19 inducers (such as carbamazepine, norfluoxetine, etc.) within 5 half-lives of the inducer plus 14 days prior to the first dose of study intervention.
• * Use of CYP2C9 and CYP2C19 inhibitors within 1 week of first dose of study intervention or within 5 half-lives (if known) of the inhibitor, whichever is longer.
• * Unable to stop long-acting antihistamines within minimum wash out period required for SPTs at screening and site visits
• * History of or significant risk factor(s) for cardiovascular disease