Hi, Thanks for writing to us. A swollen lymph node just indicates infection in the area that drains into that particular lymph node. So the sore on labia is basically leading to inflammatory swelling of lymph node. To help the node subside the sore should subside. This can be done by doing warm water compresses followed by application of topical antibiotic over the sore. If required oral antibiotic should be take. Now whether the lesion is a boil or herpes infection it can only be decided by clinically examining the lesion. Hope that helped. Take care