Hypersensitivity reactions to the commonly used denture base resins are infrequently reported. When they have been reported, most acrylic hypersensitivity reactions have been described as local contact reactions with few reports identifying any significant systemic symptoms. This paper reports a case where the patient suffered extensive systemic symptoms which were strongly linked to denture wear. A variety of alternative dentures of different resin content were constructed over time with varying reactions. The patient was patch-tested and responded with positive reactions to pure dye samples supplied by manufacturers of the resins. She also failed to react to dentures made in a clear acrylic with no dye components. These factors strongly support the hypothesis that the reactions experienced by this patient to some denture resins was the result of the incorporated colouring agents. It is therefore suggested that in cases where a hypersensitivity reaction with systemic manifestations to a denture base resin is suspected, questioning with regard to other reactions to colourants and patch testing for dyestuffs should be considered in addition to the use of a resin with no colouring agents in construction of replacement prostheses.