4 days Post septorhinoplasty, I picked on the dried blood on the entrance, could I have damaged it?

It is common to have dried blood in the nostrils following rhinoplasty. In most cases there are incisions placed just inside the nose for rhinoplasty and sutures to close these. Blood can tend to dry in this area. If you removed some of this dry blood, it is unlikely that you damaged anything deep such as the cartilage. However, if you had a lot of bleeding after the dried blood was removed, you may have opened the incision slightly - this should heal without a problem. If you are concerned, you should contact your surgeon and describe what happened to get the appropriate guidance.

You should not pick at the dried blood. I usually have patients gently cleanse the area with peroxide and water.  Best to ask your surgeon what he suggests.