Biomarkers of Cockroach Sublingual Immunotherapy 2

Inclusion Criteria: * Have a history of perennial allergic rhinitis, asthma, or both, before study entry. For those with asthma: 1. a diagnosis of asthma will be defined as a report by the participant that they have had a clinical diagnosis of asthma made by a physician over a year ago 2. the participant's asthma must be well controlled as defined by: ii. a forced expiratory volume at one second (FEV1) greater than or equal to 80% predicted value with or without controller medication ii. albuterol use for no more than 3 days per week in each of the previous 2 weeks for asthma symptoms (not including exercise prophylaxis) * Are sensitive to German cockroach (Blattella germanica) as documented by a positive (\>/=3 mm greater than negative control) skin prick test result and detectable German cockroach specific IgE (\>/=0.35 kUA/L) * Have no known contraindications to therapy with glycerinated German cockroach allergenic extract or placebo * Parent or legally authorized representative (LAR) of child is willing to sign the written Informed Consent prior to initiation of any study procedure Exclusion Criteria: * Are pregnant or lactating. Females must be abstinent or use a medically acceptable birth control method throughout the study (e.g. oral, subcutaneous, mechanical, or surgical contraception) * Cannot perform spirometry or peak flow at screening * Have an asthma severity classification at recruitment of severe persistent, using the National Asthma Education and Prevention Program (NAEPP) classification, as evidenced by at least one of the following: 1. requires a dose of greater than 500 mcg of fluticasone per day or the equivalent of another inhaled corticosteroid 2. have received more than 2 courses of oral or parenteral corticosteroids within the last 12 months 3. have been treated with depot steroids within the last 12 months 4. have been hospitalized for asthma within the 6 months prior to recruitment 5. have had a life-threatening asthma exacerbation that required intubation, mechanical ventilation, or that resulted in a hypoxic seizure within 2 years prior to recruitment * Do not have access to a phone (needed for scheduling appointments) * Have received allergen immunotherapy in the last 12 months prior to recruitment or who plan to initiate or resume allergen immunotherapy during the study * Have previously been treated with anti-IgE therapy within 1 year of recruitment * Have received an investigational drug in the 30 days prior to recruitment or who plan to use an investigational drug during the study * Have in the last 3 months prior to recruitment experienced on average \>/=1 day per week any of the symptoms below: 1. nausea or vomiting 2. abdominal pain or cramps severe enough to interfere with daily activities (excluding those associated with menstruation). 3. diarrhea * Refuse to sign the Epinephrine Auto-injector Training Form Participants who meet any of the following criteria are not eligible for enrollment and may not be reassessed. Participants are ineligible if they: * Do not primarily speak English * Plan to move from the area during the study period * Have a history of idiopathic anaphylaxis or anaphylaxis grade 2 or higher * Have unstable angina, significant arrhythmia, uncontrolled hypertension, history of autoimmune disease, or other chronic or immunological diseases that in the opinion of the investigator might interfere with the evaluation of the investigational agent or pose additional risk to the patient (e.g., gastrointestinal disease, gastroesophageal reflux disease, chronic infections, scleroderma, hepatic, and gallbladder disease) * Are using tricyclic antidepressants or beta-adrenergic blocker drugs (either oral and/or topical route\[s\] of administration)