Labial adhesions in prepubertal girls
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 fatty folds of skin which develop hair on the outer surface at puberty. The labia minora are a modified skin structure forming small flaps covering the vagina. They are much smaller in infants than in adult women. In adults, prominent sebaceous glands may be observed on the labia minora.
What are labial adhesions?
Labial adhesions mean the labia minora are stuck together. This is sometimes called 'labial fusion'.
Labial adhesions since birth or preburtal adhesions are known as primary labial adhesions and are described here.
Secondary labial adhesions follow atrophy or resorption of the labia and/or scarring. This usually occurs later in life but may rarely affect infants and children with inflammatory skin diseases such as lichen sclerosus. These diseases may result in shrinking or complete absence of the labia minora.
Primary labial adhesions most commonly affect prepubertal girls aged 3 months to 8 years.
On close inspection, the lips are completely or partially closed together, with a central line. A membrane may be seen covering the vaginal opening between the labia minora. It usually starts at the back of the vaginal opening and leaves a gap at the front.
Primary labial adhesions don't usually cause any problems in prepubertal girls.
- Urine may form a puddle in the vagina behind the adhesions, dribbling out when the child stands after going to the toilet.
- There is an increased risk of urinary / bladder infections.
What causes labial adhesions?
Primary labial adhesions arise in infants when there is very little circulating oestrogen hormone (American spelling estrogen). It is thought the adhesions occur after local irritation, e.g. by urine, scratching or uncomfortable underwear (contact irritant dermatitis), or after urinary infection.
Other disorders should be ruled out:
- Scarring due to trauma including sexual abuse
- Secondary labial adhesions due to inflammatory skin disease
- Ambiguous genitalia (intersex disorders)
- Imperforate hymen or other structural disorders
Treatment of primary labial adhesions
If the adhesions are mild and causing no problems, treatment is not required and the labia may be expected to separate by themselves at puberty. An emollient can be applied if the vulva is irritated.
If treatment is necessary, oestrogen cream may be prescribed to apply to the labia and is usually successful. At first a small amount is applied once daily for 2-4 weeks. Once the labia are separated, oestrogen cream can usually be stopped and replaced by an emollient cream for a few months. In some girls, oestrogen cream may need to be applied intermittently (perhaps once or twice weekly) until puberty is established.
Gentle division of the adhesions may be possible by simply stretching the two sides until they separate. But this may cause further irritation so that the adhesions recur.
Surgery may be required to divide severe fibrous adhesions, often using local anaesthetic cream but sometimes requiring general anaesthesia. Oestrogen cream is usually prescribed afterwards to prevent the labia sticking together again.
Prevention of labial adhesions
Prevention is not always possible, but it may help to minimise contact with irritants. Wash minimally, using non-soap cleanser. Avoid bubble baths.