Observational StudyRegistry of Asthma Characterization and Recruitment 3 (RACR3)

Inclusion Criteria:

1. Participant is either:

1. At least 18 years old, willing and able to provide informed consent at the time of enrollment
2. Under the age of 18, accompanied by a legal guardian who is willing and able to provide informed consent at the time of enrollment
2. Participant has a primary place of residence within the Office of Management and Budget (OMB)-defined Metropolitan Statistical Area (MSA)

Exclusion Criteria:

1. Participant does not speak English or Spanish and/or guardian does not speak English or Spanish
2. Participant does not have access to a phone, either personal or public, with regularity that could be used for scheduling and safety follow-up
3. Past or current medical problems or findings from physical examination or laboratory testing, 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 affect the quality or interpretation of the data obtained from the study

Participants who are pregnant or lactating will not be excluded or discontinued from the study, but will not undergo any procedures that are prohibited during pregnancy per the Childhood Asthma in Urban Settings 02 (CAUSE-02) Registry for Asthma Characterization and Recruitment 3 (RACR3) Manual of Procedures (MOP)(e.g., allergen skin testing, spirometry) during the pregnancy.

Potential participants may be reassessed as outlined in the Protocol CAUSE-02 MOP.