Thank you for posting your query.
Based on the symptoms, multiple sclerosis (MS) is less likely. This is because MS affects only brain, optic nerves and spinal cord. So, your other symptoms most typically skin involvement can not be explained by MS.
The most likely cause in your case could be due to a collagen vascular disease or vasculitis. Was this possibilities considered ? You will require a further work up, which may include blood tests such as ANA, anti ds DNA, rheumatoid factor, CRP, ANCA, etc. If these tests were done, please share. Consultation with a rheumatologist or an immunologist would also help.
Response to steroids treatment can occur in collagen vascular disease or vasculitis also.
I hope it helps.
Dr Sudhir kumar MD DM (Neurology)
Senior Consultant neurologist