Phlyctenulosis

Attempts to Produce an Experimental Model with BCG

¹ Francis I. Proctor Foundation for Research in Ophthalmology and the Department of Ophthalmology, University of California School of Medicine, San Francisco, Calif.
² Francis I. Proctor Foundation for Research in Ophthalmology and the Department of Ophthalmology, University of California School of Medicine, San Francisco, Calif.; United States Public Health Service Fellow.

Phlyctenular keratoconfunctivitis is a clinical entity but not an etiological entity. There is general agreement that it is a manifestation of bacterial allergy, most often to products of the tubercle bacillus. The reason for the focal nature of the disease, the mechanism by tohich attacks are precipitated, and the all but specific role of Mycobacterium tuberculosis remain to be elucidated. Although bacterial hypersensitivity is a feature of tuberculosis and other types of gramdomatous disease in various species of animals, typical phlyctenulosis never has been encountered in any laboratory animal. There are numerous claims in the literature to the production of phlyctenules in laboratory animals sensitized to tuberculin and other antigens, but it is in fact doubtful whether any experimental model of the characteristic human phlyctenular keratoconjunctivitis under discussion ever has been produced. Attempts to produce phlyctenules and phlyctenular keratoconfunctivitis in rabbits in which BCG was used as the antigen have so far failed.