Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Thank you so much for replying.I don't actually remember how they ruled it out, but I brought it up to multiple specialists who had various reasons why it wasn't. But even still, I did quit vaping/nicotine for 9 months during this and the condition continued to worsen. I started using my vape lightly again recently, but I will stop 100%.Is it possibly reversible if I stop immediately? (I'm stopping regardless after reading your message).And just one more question, I also thought obvious PAD but they say it's ruled out because no atherosclerosis and normal doppler. Is that inaccurate?. ### Response: You can still have an inflammatory/autoimmune process causing similar symptoms.I dont know what workup youve had, but ruling out all autoimmune conditions is a pretty significant claim, though with the right lab work you can estimate a likelihood.Id consider some of the vasculitides/rheumatic conditions such as anti phospholipid syndrome, cryoglobulunemic vasculitis, etc. they often come with other manifestations but there is obviously not a full history and physical exam above.Many of these are associated with autoimmune diseases such as lupus, but they are not pathognomonic by any means.Have they done a biopsy?.