bleeding from nose can occur due to variety of reasons most common being trauma. other causes include nose picking, acute infection, granulomas,cancer etc etc. in your case its seems more like infective in origin your earlier episode of rhinosinusitis must have inflamed your inner parts of nose and violent sneezing must have injured small blood vessels in that area leading to minor bleeding..if bleeding continues to occur then you need to consult ENT specialist

Could be bleeding from a septal spur triggered by the violent flow of air past it due to sneezing. Drop into my clinic for a proper ENT evaluation & firther management. -Dr Gladson G Uchil ENT, Head & Neck Surgeon Healthcare@Basaveshwaranagar Bengaluru