A 27-year-old woman with recurrent aphthous stomatitis failed to improve with several forms of therapy, including the use of tetracycline compresses. Cultures of the aphthae yielded heavy growth of αhemolytic streptococci resistant to tetracycline but sensitive to cephalosporins. Application of 1% cephalexin monohydrate compresses to the oral lesions produced rapid relief of pain and noticeable healing at this time as well as during later attacks.
Skin testing showed marked hypersensitivity to α-hemolytic streptococci with extension of the allergic reaction for 23 cm along the adjacent major lymphatic vessel. Intradermal injection of an autogenous streptococcal vaccine produced not only 50 mm of erythema and induration but also a transient flare-up of the patient's oral lesions. A series of vaccine injections was associated with a progressively diminishing cutaneous response as well as clinical amelioration.
Shore RN, Shelley WB. Treatment of Aphthous Stomatitis by Suppression of Intralesional Streptococci. Arch Dermatol. 1974;109(3):400-402. doi:10.1001/archderm.1974.01630030058016