HI Pat, YES you are right, allergies can occur for sure and they must check it out. To tell you the truth, the detail guys who came to my office told me it was really the same as the household superglue, I never looked at the ingredients and compared to household superglue. One would only use it for the superficial tissues to close, if the wound is deeper a subcutaneous suture would be put in first to pull things together at that level and then approximate the laceration or scalpel line edges with the glue. Works very well as long as you take your time and approximate the edges well and carefully. NO tape over the area is needed and should not be applied since if you do that tape will be permanent for months until that tape wears off. :=) YOU are correct in that if someone thinks they may be allergic they should be tested as you suggest, with a drop on the skin and leave it for a prescribed amount of time to make sure it does not cause a bullae (blister) or any rash.