diethyl-fumarate and Urticaria

To investigate the mechanisms of non-immunologic contact urticaria (NICU), the effects of 1g + 1g of acetylsalicylic acid (ASA) on contact reactions to methyl nicotinate, diethyl fumarate, benzoic acid, cinnamic acid, cinnamic aldehyde and dimethyl sulfoxide were studied in 21 test subjects. Erythema and edema reactions were observed visually, and the changes in the skin blood flow were monitored using laser-Doppler flowmetry. ASA had a significant inhibitory effect on erythema from all 6 agents and also on edema from all substances except dimethyl sulfoxide. The mechanism of the effect may be a result of the inhibitory influence of ASA on prostaglandin bioformation. Thus, to avoid false negative test results, non-steroidal anti-inflammatory drugs should not be used during NICU tests.

Topics: Acrolein; Adult; Aspirin; Benzoates; Benzoic Acid; Cinnamates; Dimethyl Sulfoxide; Female; Fumarates; Humans; Irritants; Male; Nicotinic Acids; Ultrasonography; Urticaria

The contact urticariagenic properties of diethyl fumarate were studied using the guinea pig ear swelling assay and by open application on the human upper back skin. Diethyl fumarate caused non-immunologic contact urticaria in both human and guinea pig skin, and the reactions exhibited similar dose dependency and timing of maximal response.

Topics: Adult; Animals; Dermatitis, Contact; Female; Fumarates; Guinea Pigs; Humans; Male; Middle Aged; Urticaria

The decrease in the swelling capacity and the length of the refractory period after nonimmunologic contact urticaria produced by one application of six human nonimmunologic contact urticaria agents was studied with the use of the guinea pig ear test. On retesting 1 day later, all substances (benzoic acid, cinnamic acid, cinnamic aldehyde, diethyl fumarate, methyl nicotinate, and dimethyl sulfoxide) showed reactions decreased by at least 50%. This decrease was most marked with cinnamic aldehyde (91% decrease), cinnamic acid (88%), and benzoic acid (86%). The tachyphylaxis was not specific to the substance producing it; reactivity to other contact urticaria agents decreased as well. The refractory period was 4 days after methyl nicotinate, 8 days after diethyl fumarate and cinnamic aldehyde, and 16 days after the other agents. These results suggest the following practical application: there is a need for (1) appropriate scheduling in the reuse of animals for testing for nonimmunologic contact urticaria and (2) an awareness of possible false-negative results in human tests for this form of urticaria because of tachyphylaxis.

Topics: Acrolein; Animals; Benzoates; Benzoic Acid; Cinnamates; Dimethyl Sulfoxide; Ear; Female; Fumarates; Guinea Pigs; Humans; Male; Nicotinic Acids; Tachyphylaxis; Time Factors; Urticaria

Topics: Adult; Dermatitis, Contact; Female; Fumarates; Humans; Urticaria