Using topical medications while pregnant

Posted By Joanne on May 11, 1998 at 11:07:19:







I have a skin condition known as acne rosacea.  The flare ups have gotten worse since I am pregnant (either because of the hormones or because I stopped using my medications when I found out I was pregnant). My dermatologist prescribed Sulfacet-R and Topical erythromycin.  I believe the erythromycin is Pregnancy Cat. B but the Sulfacet is Category C.  
1. Are these medications fairly safe to use or should I discontinue use until after I give birth?  and
2. What do the various Pregnancy Categories mean?