health question help please?

[Sarah]

i have been getting rashes on my body mostly my arms, hands, legs and feet that would last about two weeks. this started about 4yrs ago on and off. i get it once or twice in a year. sometimes big outbreak sometimes small. i have seen many dermatology's or skin docs. still i haven't received answers. they told me im fine, i don't have any allergic reactions, no disease nothing im healthy. my guessing to this question is my habit of smoking cigarettes and weed. do you think i could be allergic to those??????? this is really messing up my body. WHAT DO YOU THINK