my son is 4 years, he was treated for pneumonia 3 months ago through iv injections on the wrist,2 days after completions of the iv he started itching all over the body and he had rashes which turned into black spots after drying especially on hands and legs,took him to a doctor who gave him aerius syrup for ten days 3 days after starting administering aerius his lips started turning black now they they are completely black and he is still itching on legs and hands which are now black spotted. what is causing all these??