The purpose of this study is to determine whether a neuropeptide, substance P, when injected along with an allergen, such as ragweed, can reduce allergic reactivity.

Allergic Rhinitis (Hay fever) affects many children and adults and is a risk factor for development of asthma. This study utilizes the neurotransmitter, substance P, a small molecule which is present in nerve endings, the brain, skin, lungs and the gastrointestinal tract. Subjects will receive substance P and a low dosage of an allergen, such as ragweed in an attempt to reduce allergic reactivity.

Inclusion Criteria:

• positive immediate type skin test to ragweed or grass pollen or a third (standardized) allergen if both ragweed and grass pollen allergen are not positive
• volunteers should be available for allergen injections and then cutaneous titrations for approximately 1 year from the start of the enrollment period

Exclusion Criteria:

• volunteer is pregnant or lactating
• abnormal electrocardiogram for subjects over 50 years of age
• use of beta adrenergic antagonists or tricyclic antidepressants