A 60-year-old executive consulted me at 9 a. m. on June 7, 1955, on account of an acute painless swelling of the left side of the lower lip, which began sometime during the night. He was awakened at about 3 a. m. by an uncomfortable sensation of fullness in his lower lip and on investigation found it hot and swollen. Since then and slowly his lip became reduced in size, but it was still quite noticeable at the time of this consultation. (Later in the day the lip returned to its normal size.)
The sequence of events which preceded was reconstructed as follows: At about 11 p. m., June 6, 1955, and just before retiring he smoked a filter-tip cigarette. He experienced no particular sensation at the time. He recalled that this was the first time in a long time that he had smoked a filter-tip cigarette and that