Will most people who are allergic to eating fish exhibit and allergy to taking supplements containign DHA or DHA/EPA?

Fish allergies are generally due to the proteins/ peptides in fish. A number of high quality omega-3 supplements containing DHA/EPA are available which are essentially devoid of proteins. While it is expected that these are unlikely to cause allergic responses in those who are allergic to fish/ seafood, it is advisable to consult with one's physician and/ or allergist regarding this question before consuming such products.