What Causes Perineal Tingling And Painful Spot On Labia Majora?

Is there any other condition that would cause perineal tingling and painful single pimples on the labia majora, other than HSV2? About 6 at a time, they appear in different genital areas, then disappear without scarring. The pimples are shiny (but no frank fluid observed) and stay for 2 wks at a time. Symptoms have lasted for 2 months now. No vaginal drainage. Two inconclusive cultures x2. Symptoms started 3 mo out of possible exposure and Igg and Img were negative. Feels much worse than it looks. Valtrex 1000 mg BID did not help. What else can it be?