Five cases of photocontact dermatitis due to topical ketoprofen: photopatch testing and cross-reaction study.
BACKGROUND
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.


CONCLUSIONS
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.
Matsushita
T
T
Department of Dermatology, The Jikei University School of Medicine, Tokyo, Japan.
Kamide
R
R
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects* / Q000737:chemistry; D003429:Cross Reactions; D017454:Dermatitis, Photoallergic / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007660:Ketoprofen / Q000009:adverse effects* / Q000737:chemistry; D008297:Male; D015394:Molecular Structure; D010328:Patch Tests
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007660:Ketoprofen