It certainly isn't herpes, which consists of a cluster of blisters in one spot along the lip margin, lasts 7-10 days, and goes away, though it may recur later in the same place.
As for vitamin deficiency, that too is remote. Though people often refer to the possibility, I agree it makes little sense in your situation.
Sometimes yeasts which live in the mouth and gut congreagte in the corners of the mouth at night. This generally just affects the corners, not the cheeks, nose and chin.
Perhaps you have mild roscaea. If you are using any cortisone creams, I suggest you stop. Definitive treamtent may have to wait till after you deliver and finish nursing, but I very much doubt you are contagious in any way.
Best.
Dr. Rockoff
the corners of the mouth at night".
Does anyone know how to prevent this? I get "cracking" at the corners of my mouth which don't heal for weeks-monthes. It's very painful and quite unattractive.
thank you