a·top·ic 
(ā-tŏpĭk)
(ā-tŏpĭk)adj.
Of, relating to, or caused by a hereditary predisposition to developing allergic reactions, such as hay fever, asthma, or urticaria, after exposure to specific antigens such as pollen, food, and insect venoms.
[From Greek atopiā, unusualness, from atopos, out of the way : a-, not; see A-1 + topos, place.]
ato·py (ătə-pē) n.