Severe anaphylactic reaction to diclofenac.

Arachidonic acid metabolism takes place via the cyclo-oxygenase and the lipo-oxygenase pathway. Both the pathways produce potent mediators of a multitude of immune-induced and inflammatory reactions. Any blockade of cyclo-oxygenase pathway (COP) shunts the metabolism towards the lipo-oxygenase pathway (LOP) and can potentially increase the side-effects of that pathway by augmented production and release of cysteinyl-leukotriene.1 Diclofenac is a Non steroidal Anti inflammatory drug with specific inhibiting actions on cyclo-oxygenase-1 (COX-1) and cyclo-oxygenase-2 (COX-2) with relative equipotency. The drug has also been proven to be multimodal in action with extended spectrum of targets including thromboxane-prostanoid receptor, arachidonic acid release and uptake, lipoxygenase enzymes, and activate the nitric oxide-cGMP antinociceptive pathway.2 As the drug has effects on both pathways (COP & LOP), it has been considered safer than other NSAIDs and is extensively used as an analgesic and anti-pyretic in both adults and children. We present a case of a young male who had a severe life threatening anaphylactic reaction to diclofenac.