I am 54 and use hair dye but every time i get reaction and want to know what kind of dyes shall i use and what over-the-counter medecine i can use?

Stop using the dye: It sounds like your body is telling you something! if you are having a reaction to a chemical, i would stop exposing yourself to such chemicals. The kind of reaction is important to note as well - some are on the skin but some can be more systemic. Some less chemically based hair coloring agents exist such as henna that might not cause a problem. Talk with your beautician.

P-phenylenediamine: Common allergen in hair dye to avoid is p-phenylenediamine. This is also added to henna tattoos to make them darker on the skin so avoid that if this is truly your allergy. I believe that hair dyes made with vegetable dyes are your only options. Would love to hear if other physicians have some pearls.