Swelling and irritation of the vulva that flares when water touches it usually points to either a contact reaction or a local infection. Soaps, shower gels, intimate washes, detergent left in underwear and hair removal products are frequent triggers, and a yeast or bacterial infection can produce the same picture. Because the vulva is easy to examine and the treatments for these causes are quite different, this needs a look rather than a guess from a description.
Next Steps
Please book a gynaecologist visit for a vulvar examination. Until then stop all soaps, washes and fragranced products in that area and use plain water only, wear loose cotton underwear and keep the area dry.
Health Tips
Do not use any over the counter cream on the vulva before it is examined. Steroid and antifungal creams applied to the wrong cause can make the swelling worse.