@jw9 I agree with you - "slippery" is a great description. 40 years ago my diagnosis was fibromyalgia. 10 years later it was seronegative Sjogren's, then 15 years ago MCTD, now back to Sjogren's but with Lupus markers showing up. And of course the psychologizing along the way delayed any serious efforts at appropriate treatment. We are still in the dark ages of understanding autoimmunity. But getting better, I hope.