HMGB1 and toxic epidermal necrolysis: In conclusion, this study has shown that HMGB1 is elevated in patients with SJS/TEN, with levels being higher in blister fluid than in serum, but this may not be the case in all patient groups, particularly where the underlying concomitant disease (e.g. advanced HIV disease, as in our Malawian patients) and its treatment can affect HMGB1 levels.