Q&A: What is the "rash of pregnancy?"

For unknown reasons, probably immunological, expectant mothers occasionally get a rash that consists of slightly raised little red bumps that vary from unnoticeable to insanely itching. It is called "puerperal urticaria of pregnancy," or "PUP." That overinflated name means rash during pregnancy that causes little red spots.

In my practice, I see it about one out of twenty patients. Usually just reassurance is all that is needed when the case is mild. My worst case of it resulted in fairly serious secondarily infected lesions, requiring antibiotics to get the infection cleared up, then steroids to keep the PUP at bay. Mother and baby did fine, but I can tell you I was a little concerned about almost six weeks of medication for the patient, called Medrol dosepacks (what is prescribed with poison ivy). The chances of PUP happening in subsequent pregnancies are increased, but only because you have proven you can get it at all. It is entirely possible to escape PUP in subsequent pregnancies as well.