Extremely short question. I pour a bit of hydrogen peroxide in my bathroom sink and it starts to sizzle, almost the same way it does on the open wound. Why? What elements in there it reacts with?
Hydrogen peroxide contains an peroxide linkage and it decompses rapidly to give oxygen.
But when substances like detergent come in its contact in a bathroom (as in the question) it not only catalyses the reaction but if it was a foam making detergent it would make the decomposition process more evident and visible as oxygen bubble would produce effervescence in foam.