Labial adhesions in adult women

What are labia?

Labia is the medical term for lips. Labia usually refer to the lips of female genitalia. The labia cover and protect the urethral opening (the urethra is the passageway to the bladder) and the vagina. There are two outer lips, the labia majora, and two inner lips, the labia minora.

The labia majora are usually covered with sparse pubic hair and are considered a skin structure. The labia minora are an interface structure with an outer hair-free skin surface and an inner mucosal surface. The labia minora look like flaps or wings, and they can be a few millimetres to several centimetres in length.

What are labial adhesions?

Labial adhesions mean that the labia minora are stuck together (fused). Adhesions rarely result in complete labial fusion; more often it is partial. The adhesions may also be called bridging, as they join the right and left side of the vulva. The term may also be used when labium minorum fuses with labium majorum.

Secondary labial adhesions usually occur after menopause. Labial adhesions in prepubertal girls are often present since birth and are known as primary labial adhesions.

What causes labial adhesions?

Secondary labial adhesions may be due to oestrogen deficiency, particularly in non-sexually active women after the menopause. They may also be caused by scarring or fibrous tissue that forms after severe inflammatory skin disease, surgery or trauma. The most common causes are listed below.

• Oestrogen deficiency associated with atrophic vaginitis
• Vulval lichen sclerosus
• Erosive lichen planus
• Mucous membrane pemphigoid
• Behcet syndrome
• Stevens-Johnson syndrome / toxic epidermal necrolysis
• Vulval cancer
• Complications of childbirth
• Female circumcision operation (illegal in many countries)
• Complications from vulvectomy

Clinical features

Labial adhesions joining the left and right labia minora result in a narrowed vaginal opening or introitus.

The vaginal opening is normally several centimetres in length and in adults can easily stretch to accomodate a penis during sexual intercourse, and at the end of pregnancy, a baby's head. When the labia are fused together, the opening is smaller and can't stretch. It can be as small as a pinhead when labial adhesions are severe. Symptoms may be absent or the adhesions may lead to:

• Dribbling urine on standing up after passing urine
• Painful sex (dyspareunia)
• Other symptoms such as itch and soreness, depending on the cause of the adhesions.

Adhesions fusing a labium minorum to the corresponding labium majorum results in resorption, shrinking or disappearance of the labium minorum.

Characteristics of labial adhesions include:

• Flat appearance of the genitalia.
• Small or absent labia minora.
• Fusion can affect the anterior vulva (front) or the posterior vulva.
• Anterior fusion is often associated with disappearance or fusion of clitoral hood (the skin covering the clitoris).
• Posterior vulval fusion may be due to scarring of perineum (the tissue between the vagina and anus).
• Affected tissue does not stretch properly (loss of elasticity).

Other features depend on the condition causing labial adhesions and may include:

• Colour changes (white from scarring, red from inflammation or brown from previous inflammation)
• Blisters, erosions and ulcers
• Patches or lumps.

The internal tissues of the vagina may be quite normal but inflammation and scarring may affect the vaginal lining as well as the external genitalia in some rare inflammatory skin disorders such as erosive lichen planus. The vagina may also be scarred following surgery or trauma.

Images of labial fusion ...

What are the complications of labial adhesions?

Partial labial adhesions may be unobserved but often, symptoms and complications arise. These include:

• Tissue splitting with painful fissures at the top and/or bottom of the vaginal opening (fissured fourchette)
• Difficulty or inability in inserting a tampon during menstruation
• Complete inability to have normal sexual intercourse (apareunia)
• Difficulty in wiping dry after passing urine
• Dribbling of urine that has formed a puddle behind the fused tissue.

Complete labial fusion means that urine and vaginal fluids including menstrual blood build up behind the fused labia; this is an emergency and urgent medical assistance should be sought.

What treatment is available for labial adhesions?

Treatment depends on the cause of the fusion. It does not always require specific treatment.

• Intravaginal oestrogen cream, most often prescribed after menopause
• Manual division by gently stretching the two sides until they separate
• Topical corticosteroids to control inflammation
• Regularly stretching the opening using fingers, vaginal dilators or regular sexual intercourse
• Surgery to remove scar tissue (Fenton procedure)
• Surgery to bring out uninvolved vaginal tissue to the skin surface (perineoplasty).