hi i had gone through your query and understand your concerns. i would come up with the possibility of ALLERGY
may be the underlying cause for your sufferings.
-insect bite is the triggering factor for your allergic reaction
-inherited tendency is the other possible cause
i advise you taking Homeopathic
medicines gives safe and permanent cure for your allergic complaints
consult your local homeopathic physician for correct diagnosis of the case and remedy to fit your complaints
I hope this is helpful for you, thank you