What Are Labial Adhesions?

Overview

Labial adhesion, also known as labial fusion, is a condition where the inner lips of the vulva become stuck together. While the exact cause is unknown, it is believed that low levels of oestrogen play a role in the development of labial adhesions. This condition is commonly observed in people who are assigned female at birth who have not yet reached puberty, but it can also occur in people who have recently given birth or are going through menopause. Labial adhesions may be asymptomatic, but in some cases, they can cause issues with urinating, or urinary tract infections. Treatment is usually not required as labial adhesions often resolve on their own, but in cases where symptoms are present, treatment options include oestrogen creams and, rarely, surgical intervention.

Causes of labial adhesions

Although it is currently unknown what causes the condition, it is often found that lowered oestrogen is a common factor amongst people with labial adhesion. Without oestrogen, the labia can become inflamed or irritated (otherwise known as vaginitis), leading to them becoming ‘sticky’. As the oestrogen levels remain low, the labia may become more firmly joined. Groups of people considered to have low oestrogen are girls or people assigned female at birth (AFAB) yet to start puberty, which is the most common population to be impacted by this condition. Other groups may consist of people who have recently given birth, or are going through the menopause. Labial adhesions that coincide with expected low levels of oestrogen are considered to be primary labial adhesions.

Alternatively, secondary labial adhesions are reported less in children, and is usually related to ongoing scarring, sometimes due to conditions like lichen sclerosus or dermatitis.

Signs and symptoms of labial adhesions

Many findings of labial adhesion are accidental, found in routine checks or examinations for other conditions. This is because the majority of patients have no symptoms.

Rarely, there are some minor symptoms, such as:

• Urine getting trapped behind the adhesions and being released later when the child stands up or moves around.
• An increased frequency of urinary tract infections.
• In rare cases, the adhesions can lead to irritation, discomfort and soreness

It is also important to rule out other disorders that could cause the above symptoms or could appear clinically similar to labial adhesion. This can include structural abnormalities, where the genitalia may have developed differently since birth. Trauma-related scarring from sexual abuse or the result of female genital mutilation (FGM) can also look clinically similar to labial fusion. 

Management and treatment for labial adhesions

The majority of the time, treatment is not required as the adhesion will naturally resolve itself, the labia separate on their own, found in up to 80% of cases.¹ Cases where treatment is recommended is usually due to the presence of discomfort or other symptoms. In extreme cases, this can mean surgery, but typically, an oestrogen ointment is prescribed.

Oestrogen creams are used daily for six weeks, or until the membrane where the labia are fused begins to dissolve. Only a small amount needs to be used, applied directly to the central line of the adhesion. After separation, nappy rash cream or other emollient should also be used to allow for efficient and optimal healing. This will mean recovery is easier, preventing a new membrane to develop fusing the labia together again. 

If used for longer than a couple weeks, side effects are more likely to appear, which can include darkening of the skin where the ointment is applied (which can be less noticeable on darker skin tones), as well as tenderness in the chest.² However, these should disappear after treatment ceases to be used.

Rarely, surgery is needed to treat labial adhesion, so is only utilised in the case of oestrogen cream not working. Surgical separation of labial fusions is a relatively straightforward procedure. With the use of gentle manual techniques or a small blunt probe, a doctor can easily separate the fused labial tissues. The surgery is typically performed under anaesthesia to ensure the patient's comfort and minimise any potential pain or distress. 

To facilitate proper healing and prevent the recurrence of fusion, again, application of an emollient such as nappy rash cream or vaseline to the labial edges for a few weeks post-treatment is recommended.³

It's important to note that there is a significant chance of the fusion membrane returning, regardless of whether the treatment involved oestrogen cream or surgical intervention. Close monitoring and appropriate follow-up care are essential in managing labial fusion cases. 

Diagnosis

Due to the mild nature of symptoms presented with labial fusion, it is often missed with no complications to the patient. In the case that the condition is not asymptomatic, and the person sees a healthcare professional, diagnosis is simple and can be made from visual inspection alone. This may also be picked up in a routine gynaecological appointment.⁴

A white or grey line between the labia minora indicates the presence of adhesion. It's important to distinguish labial adhesions from other conditions such as imperforate hymen or vaginal agenesis, which have different characteristics.⁵ While labial adhesions can sometimes obstruct the urethra, it is rare and does not typically result in an inability to urinate.

FAQs

How can I prevent labial adhesion?

There is no known way to prevent labial adhesion in the first instance, but it is possible to prevent fusion from happening again. Applying nappy rash creams, zinc oxide creams like Sudocrem or Vaseline can help the skin heal and stop the return of the sticky texture that means the labia adhere in the first place. With babies and young children, it can also be helpful to avoid strong or perfumed soaps, as they can irritate the skin and cause inflammation.³

How common are labial adhesions?

Labial fusion is found to affect up to 2% of prepubertal people assigned female at birth (AFAB). When it comes to other groups who are at risk of having the condition, cases like this are typically rarer.²

Who is at risk of labial adhesions?

Although the cause is not known, it is thought that low oestrogen levels makes labial adhesion more likely. This means people with lower amounts of oestrogen including prepubertal children assigned female at birth, people who have recently given birth, or people experiencing menopause are more at risk.

When should I see a doctor?

As mentioned, the condition is usually asymptomatic, and will not cause any harm as the labia will separate naturally as oestrogen levels begin to rise. However, if symptoms are present, like urine getting trapped behind adhesions or increased numbers of urinary tract infection, consult a healthcare professional.

Summary

Labial adhesion is a relatively common condition characterised by the forming of a membrane between the labia minora, fusing them together. Thought to have correlation with low oestrogen levels, most cases are asymptomatic and resolve when oestrogen levels are restored or developed. When this is not the case and the individual is impacted by issues surrounding urination and discomfort, treatment using oestrogen cream is prescribed, with surgery as a last resort. The essential point to take away is that, although fusions may come back, this is usually a self-correcting condition, with little to no impact on the individual or their future health.