Causes of vulval pain are due to all except:
Vulval pain syndrome
Vulvar pain sensation may be burning, stinging or irritation. It may be due to several reasons:

Aphthous ulcer
Vulval dermatoses
Herpes genitalis
Pudendal or genitofemoral nerve neuralgia
Vulvodynia (burning vulva syndrome)
Vulval vestibulitis syndrome
Referred pain from urethral or vagina
Psychological
Neuralgia of the genitofernoral nerve
Herpes
Vulval vestibulitis syndrome
Lichen sclerosus