For the record. SJS Syndrome occurs quite rarely but it happens. The list of triggers is extensive. The reaction to B1 seems both unusual and severe.
We who supplement diversely ought be aware. Here's a pretty fair listing.
Triggers for Stevens–Johnson syndrome / toxic epidermal necrolysis
December 2016.
Medicines (listed alphabetically)
This list of drugs known to cause SJS/TEN is not exclusive.
dermnetnz.org/topics/sjsten...
Foods and herbs next on url.