Thanks, I have an appointment at Univ of Penn in 2 weeks with an associate of Dr. Merkel. She specializes in vasculitis. The irony is that my worst complaint is a bout for a year and a half of sinusitis, finishing off 2016 with pneumonia and the flu. After several rounds of Doxycycline, I am feeling better than I've felt in years. I gained 5 pounds and have been working out 2 hours a day for the last month. I'm so hesitant to take medication when I feel this good. It doesn't make sense to me. I teach children and they are major germ carriers, and being on meds that compromise your immune system may mean I have to quit my job.