You are suffering from chronic urticaria
. It may be idiopathic or autoimmune. Usually eating something different plays role in acute urticaria. Still its good to have routine healthy and hygienic dietary habits.
Several drugs like analgesics, stress
etc. can aggravate the problem, so try to stay away as far as possible.
Your family members will not contract it from you.
Kindly visit a dermatologist
and remember to take the medications prescribed at a fixed time daily.