Cross-sensitivity among oxicams in piroxicam-caused fixed drug eruption: two case reports.

Fixed drug eruption (FDE) caused by oxicams is very rare. There are few reports of FDE induced by piroxicam, and this explains why cross-sensitivity among oxicams (piroxicam, tenoxicam, and droxicam) has been studied in only one patient. The patch test on residual lesions has lately been used by some authors in FDE diagnosis with variable results. We describe two cases of piroxicam-caused FDE and demonstrate cross-sensitivity among piroxicam, tenoxicam, and droxicam in both of them. One patient had residual lesions and the patch test was useful for diagnosis and cross-sensitization studies. The second patient had no residual lesions, and the patch test was negative on normal but previously affected skin; therefore, the study was performed by single-blind controlled oral challenge.