YES! Lupus can affect the nails. Actually anything unhealthy happening in your body can show up in your nails.
Nail changes occur in about 10 percent of patients and consist of cracking, curling, and even loss of nails. These symptoms are due to the changes in the small vessels of the nail bed. Often times people with lupus will have redness around the base of the nail as well.
I did read that dry, brittle nails can come from SJs as well. Makes sense since it causes dryness and it would be taking the moisture away from the nail bed.
also remember that the meds we take can affect our system which in turn can eventually effect our nails
Hope this helps!
Below are a few links about nails and AI disease