My 87 year old dad was given macrodantin following a kidney stone removal procedure and broke out with red rash and complaining of numb feet. The ER doctors said it was allergic reaction to the macrodantin - gave him Benadryl and it seemed to clear up. Four days later he is now breaking out again and complains of sore chest too. Could the drug still be in his body.. He last took a dose12 days ago.