Hey Fubar, I've been going through crazy MS worries myself and although I haven't experienced this particular symptom, it sounds to me like something that could easily be caused by anxiety. A few weeks ago I was studying for some very tough exams and was under a huge amount of pressure. Needless to say, my eyes and muscles were twitching all the time, I had a slight tremor in my hands, my muscles were tight, and my right foot felt like it was going numb. Of course, these symptoms simply added to my stress, which fuelled the symptoms, and on and on the cycle continued. At some point I began to feel itchy and, predictably, started worrying that this was a sensory disturbance caused by MS. Well, wouldn't you know it, my whole body started to feel itchy...my head, my face, my chest and back, my legs, even my hands and feet. This went on for a few days and went away after I wrote my exams.
I think that one of the reasons why this particular symptom went away so quickly is because I quickly realized that the itchiness could not be caused by MS. You have to look at the physiological changes responsible for MS. As you know, MS is caused by lesions which slowly accumulate in the CNS. The progression, even in primary progressive cases, is quite slow (in comparison to cancer for example). If it weren't, all MS patients would be in a wheelchair in less than a year. Knowing this, I realized that MS would not, all of a sudden, cause itchiness in all parts of my body. It might start off in one hand, then start affecting the other, etc. Over time, as the number of lesions increases, it might be possible for a person with MS to experience itchiness all over, but it wouldn't happen all at once.
This probably applies to your situation as well. When you wear clothes, you get a weird sensation in whatever part of your body is in contact with the clothing. Well, if this were truly an MS symptom, you might get a weird sensation when you put on a pair of pants (for example), but only in one of your legs or in one part of one of your legs. But would you get a strange feeling all over right from the start? I don't think so. I don't know if I'm explaining myself very well because I'm just about ready to pass out, but I hope you get my drift.