I was prescribed doxycycline for ureaplasma infection and developed a red, itchy rash over my face and body with the first dose. My doctor switched me to azithromycin, which I took without problems. A few months later the infection is back, and the doctor wants to try minocyline instead. I got a itchy rash on my chin and my neck and arms are somewhat itchy after one dose. Am I experiencing allergies to these drugs or just side effects? Should I avoid tetracyclines? Is it common to be allergic or sensitive to more than one?