The posterior fourchette is a thin fork-shaped fold of skin designed to stretch at the bottom of the entrance to the vagina. However, it sometimes fails to stretch properly, and instead splits. This is a cause of recurrent vulval pain. Pain from fissuring is often described as being 'like a paper-cut' or 'knife-like'.
Recurrent fissuring has been previously called vulval or vulvar granuloma fissuratum.
The splitting occurs when the vulva stretches, particularly during sexual intercourse. This may be because the skin is stiff, inflamed, fragile, or for unknown reasons.
Posterior fourchette fissuring may be primary, i.e., no underlying skin disease is diagnosed, or secondary to an infection or inflammatory skin disease. Common causes include:
Laceration of the posterior fourchette may also be due to straddle injury, violence or rape; in these situations bruising and other injuries may also be present.
Similar symptoms experienced in the absence of fissuring or other visible signs may be described as vulvodynia or vestibulodynia.
Most women who present with posterior fourchette fissures are sexually active and symptoms follow intercourse. Symptoms may be mild, moderate, or severe in intensity, usually resolve within a few days, and may include:
Affected women may be premenopausal or postmenopausal. Fissuring can occur at the first attempt at sexual intercourse or many years later, in women who have had children or who have never had children. They may also have other symptoms, including fissures in the skin folds elsewhere in the vulva.
On careful clinical examination, there is usually a tiny split or linear erosion at the midline of the base of the vagina on the perineal skin. Colposcopy may be necessary to see the fissure. The posterior fourchette may form a tight band or tent (membranous hypertrophy). In some cases, signs may be more impressive and include:
The vulva may appear entirely normal if the examination takes place after the fissure has healed. But often, a new fissure can appear while gently stretching the vulva.
Specific tests are often unnecessary if the history and appearance are typical.
Swabs may be taken to look for vaginal infections such as bacterial vaginosis and Candida albicans, for sexually transmitted infections or herpes virus.
Biopsy may show typical features of the underlying skin disorder. The histopathology of primary fissuring usually reveals nonspecific submucosal chronic inflammation; the clinician may consider the report nondiagnostic. Granuloma formation is rare. Scar tissue may be present.
If an underlying infection or skin condition is diagnosed, specific treatment is usually very helpful. Examples include:
Women with mild symptoms due to primary fissuring of the posterior fourchette may benefit from:
Women with severe symptoms from primary fissuring of the posterior fourchette may consider vulval surgery. Perineoplasty is a surgical procedure that is usually undertaken under general anaesthesia. The fissured skin is completely cut out and replaced by vaginal epithelium that has been undermined then advanced to cover the defect without tension. It is stitched up from front to back. Perineoplasty may allow women with posterior fourchette fissuring to resume normal and painless sexual activity but is not always successful.
Vulvovaginal Disorders: an algorithm for basic adult diagnosis and treatment — ISSVD
