What Causes Sudden Swelling Of Hands, Feet, Lips And Eyes?

I have suffered with sudden swelling of my hands, feet, lips, eyes, arms, and legs for over 3 years now. The attacks come and go seemingly for no reason. However, if I injure myself like a sctrach or a bruise I will always get an attack. I have been to 4 different dr's and they can not tell me what is wrong. Then I stumbled on Hereditary Angioedema. Looking at the photos, videos, and the discriptions from other people I truley believe that I have this condition. I would like to know if I should go back to a dermatologist or go back to my allergist for a correct diagnosis... I would welcome any suggestion that you might have! That you very much.