Fixed anaphylactic sensitization: Bromsulphalen Studies

1.1. A case of fixed tissue sensitivity of the anaphylactic (immediate wheal) type is described.2.2. Bromsulphalein injected paravascularly (subcutaneously) resulted in an area of inflammation.3.3. Intravenous injection of bromsulphalein one month after the paravascular injection produced an immediate flare-up at the site of the previous inflammatory reaction, a generalized urticaria, and systemic symptoms resembling anaphylactic shock. Both local and systemic symptoms responded promptly to epinephrine and Benadryl.4.4. The area of extravasation was found to be sensitive to bromsulphalein and a very closely related halogen analogue, giving immediate wheal reactions on intradermal testing. The whealing response could be inhibited by the prior administration of Pyribenzamine.5.5. Studies to correlate chemical structure and skin reactivity were attempted. The tetrachloro analogue of bromsulphalein yielded exactly the same reactions, but a halogen-free analogue did not react. Compounds representing component parts of the bromsulphalein molecule also failed to elicit reactions.