A recent change from Haemaccel to Gelofusin as the preferred colloid for resuscitation in our region caused us to review patients who were known to be allergic to Haemaccel. As Gelofusin and Haemaccel are both modified gelatine, it seemed likely that cross reactivity could occur. Two patients who had been diagnosed previously as having had anaphylactic reactions to Haemaccel were tested intradermally with dilutions of 1/100 of Haemaccel and Gelofusin. Both patients showed similar positive reactions to each agent. It appears that patients who are known to be allergic to Haemaccel are probably allergic also to Gelofusin. Both patients have been given new Medic Alert bracelets stating "Allergic to Haemaccel and Gelofusin".