I personally have not heard specifically of allergies to Lantus, but I have heard of people having allergies
to other insulins. The allergy is not
to the INSULIN, but
to the agents that it is suspended in. The cases I remember from other people who have written in to ask about this kind of thing were usually hives in areas near where the insulin is injected, but I seem to remember one or two that just had hives in unrelated areas.