thanks for query first of all please let me aware was there itching sensation over that knot??? has it now disappeared spontaneously???? if the ans to the above two qn are yes then probably it was localised urticaria u need not to worry u may take levocetrizine or montelukast u needs allergy test to be done u must be aware of one fact that anytime u r feeling choked in throat or feeling suffocation if this is the case u shoud have to take levocetrizine or allegra or avil or montelukast immediately and rush to the doctors because if laryngeal odema develops in urticaria it may be life threatening otherwise u need not to be worried about much