IgE antibodies against Neisseria flavescens

Bacterial allergy is still a matter of controversy. We sustain that this name should be employed only in the presence of a specific IgE against antigens from bacteria. In 100 atopic patients and 100 healthy controls with Neisseria flavescens in their pharyngeal exudates, we performed type I immediate skin tests with Neisseria flavescens and IgE-RAST throughout 1 year. Positive wheal and flare reactions were elicited in 8 of 100 atopic patients as well as in 3 of 100 nonatopic subjects. IgE-RAST/anti-Neisseria flavescens was found in 6 of the former group and in 1 of the latter. Neither late-phase nor Arthus-like reactions were recorded. Neisseria flavescens is a non-pathogenic commensal of the oropharynx with scarce antigenic properties and seems not to play an important role in these conditions (rhinitis/asthma). Bacterial immunotherapy should be considered only in the presence of specific IgE antibodies with careful selection of the bacteria or their antigens.