I believe that it could be the toxins released by the worms causing the bumps but it could also be the worms themselves.
Go to the Ask Humaworm forum here a CZ and read some of the comments there. There is one person who suffers from this and she is very knowledgeable. She also has a blog of her symptoms and treatment. Because you have MS, it could prove difficult to treat. You definitely need to see a specialist if you can find one... An infectious disease doctor may be where to start but a Parasitologist would be the best thing.
I have read that Strongyloids mimic lots of diseases such as Chronic Fatigue, Lupus, MS, etc... It may be that your MS is actually just the Strongyloid infection that you may have had for years. Something to look into. Here is some info from the Cleveland Clinic.