The purpose of this study is to find out if there is a way to treat children with peanut allergy to help lower the risk of severe allergic reactions and also cause them to lose their allergy to peanuts and to understand what happens to their immune systems when they have viral infections while on therapy. The approach we will use to treat peanut allergy in this study is a process called desensitization.

We think that children with a peanut allergy receiving peanut oral immunotherapy will be able to eat more peanuts without having a reaction by the end of the study than they could eat at the beginning. We also think that we will be able to measure changes in their immune system and their immune system's response to viruses while they are on therapy.

Peanut allergy is known to cause severe anaphylactic reactions. Compared with other food allergies it tends to be more persistent and also its prevalence seems to be rising. Currently there is no proven treatment other than strict avoidance. We are attempting to decrease the risk of anaphylaxis on accidental ingestion by desensitizing subjects to peanut using peanut oral immunotherapy (OIT). We are also studying the effect of viral infections on the immune system in children receiving peanut OIT.

Children ages three to sixteen years of age with peanut allergy will be given peanut OIT. Twenty-five subjects will also be recruited as controls. These subjects will not receive any peanut or placebo but only have skin prick testing and lab work in addition to a history and physical exam. Active subjects will undergo a double-blind food challenge at entry to verify that they are allergic to peanuts. If allergic, they will then have modified rush immunotherapy on the first day and then increase the doses at least every two weeks up to a maintenance dose of 4 grams (equivalent to about 13 peanuts). Doses will be taken daily at home except for dose increases which will be done at Children's Medical Center. Outcome variables of interest include response to double-blind placebo controlled food challenge, skin prick testing, peanut specific IgE, and adverse events. These results will be compared between the start and end of peanut OIT using appropriate statistical analysis.

Inclusion Criteria:

• Age 3 to 16 years of either sex, any race, any ethnicity, weighing at least 18.3 kg at the time of the initial visit.
• The presence of IgE specific to peanuts (a positive skin prick test to peanuts (diameter of wheal > 3.0 mm) and a positive in vitro IgE (CAP-FEIA) > 7 kU/L) measured within the past year.
• Significant clinical symptoms occurring within 60 minutes after ingesting peanuts during an observed Double-Blind Placebo Controlled Food Challenge.
• Provide signed informed consent.
• Ability to follow-up regularly for scheduled appointments.
• Females of child-bearing potential must be willing to practice an acceptable form of birth control throughout the protocol.

Exclusion Criteria:

• History of severe anaphylaxis to peanut as defined by hypoxia, hypotension, or neurological compromise (Cyanosis or SpO2 < 92% at any stage, hypotension, confusion, collapse, loss of consciousness; or incontinence)
• Currently participating in a study using an investigational new drug.
• Participation in any interventional study for the treatment of food allergy in the past 12 months or while participating in this study.
• Subjects with a known oat or wheat (because of potential cross contamination with oat) food allergy will be excluded
• Poor control or persistent activation of atopic dermatitis.
• Diagnosis of asthma and currently being treated with daily doses of inhaled corticosteroids or requiring a rescue inhaler more than 2 days per week.
• Inability to discontinue antihistamines for skin testing and Oral Food Challenges (OFCs).
• Pregnant female.
• Chronic medical condition requiring frequent use of oral steroids, chronic psychiatric illness or history of substance abuse.