I saw a 52 year-old Hispanic male as second opinion regarding a diffuse drug rash with known medication culprit. In brief, he has had three total episodes of diffuse desquamating drug rash, all with cutaneous (arms, chest) and oral desquamation and pain suggestive of SJS:
~2009: was taking a "penicillin" at the time, has not received penicillin based antibiotics since that time.
2019: diagnosed with prostate cancer, biopsy proven with local metastases.
7/10/19: underwent prostate biopsy. I do not have induction regimen of this procedure, but the following day developed mouth ulcers, cracked lips and desquamating rash. He provided pictures that corroborate classic case. It is possible that he received fosfomycin as his perioperative antibiotic. He was prescribed a mouth wash that helped gradually and the rash/symptoms resolved over weeks. No fever or arthralgia or eye involvement.
8/28/19: underwent repeat prostate biopsy; later that day (hours), developed symptoms described previously, though more severe. He did not require hospitalization, but once again review of pictures suggests SJS. I do have record of medications received that day:
once again, he was given mouth wash with slow resolution over a few weeks.
Going forward, is there any utility in further evaluation of potential culprit agent to his reactions? If so, how would you risk stratify any of these agents as likely causes, as most are not well described agents in Stevens-Johnson Syndrome?