Five cases of photocontact dermatitis due to topical ketoprofen:photopatch testing and cross-reaction study
In parallel with the popular usage of topical ketoprofen, the number of reported cases of ketoprofen-induced photoallergic contact dermatitis has been increasing. It is clinically important to know the cross-reactivity of ketoprofen in order to avoid cross-sensitization caused by several structurally similar non-steroidal anti-inflammatory drugs (NSAID) on the market. Methods:
To evaluate the spectrum of cross sensitization, photopatch testing was performed on five patients with ketoprofen-induced photoallergic contact dermatitis using ketoprofen and other structurally similar chemicals, such as oxybenzone, tiaprofenic acid and suprofen. Results:
All five patients reacted positively to ketoprofen or ketoprofen plaster on photopatch testing. All four patients photopatch tested with related chemicals showed cross-photosensitization with tiaprofenic acid and suprofen. However, none of the patients reacted positively to oxybenzone. Conclusion:
Either the diphenylketone moiety or a structurally similar tiophene-phenylketone moiety is important as the antigenic determinants of ketoprofen photoallergy. The arylpropionic acid side chain would not be involved.