Cytolytic Vaginosis (CV): Symptoms, Causes and Treatment in the UK

Cytolytic vaginosis (CV) is a relatively under-recognised condition characterised by an overgrowth of Lactobacillus bacteria. While these bacteria are typically considered the 'good' microbes that keep the vaginal environment healthy, an excessive population can lead to an overproduction of lactic acid. This results in the vaginal pH dropping to abnormally acidic levels (usually between 3.5 and 4.0), which causes the breakdown (lysis) of vaginal epithelial cells.

For many women in the UK, this condition remains a mystery because its clinical presentation is almost identical to candidiasis (vaginal thrush). Patients often find themselves in a cycle of using over-the-counter anti-fungal creams and pessaries with no relief, as these treatments do nothing to address the bacterial overgrowth found in CV.

The symptoms of cytolytic vaginosis usually fluctuate according to the menstrual cycle. They tend to be most severe during the luteal phase (the days leading up to a period) because glycogen levels rise, providing more fuel for the Lactobacilli to multiply. Symptoms often improve once the menstrual flow begins, as blood is naturally alkaline and raises the vaginal pH.

• Vaginal Discharge: Typically white, thin and watery, or thick and pasty. It is rarely chunky like cottage cheese (a hallmark of thrush).
• Vulvar and Vaginal Burning: This is often the most distressing symptom, sometimes described as a 'raw' feeling.
• Dysuria: Burning when passing urine, as the acidic discharge irritates the urethral opening.
• Dyspareunia: Pain or significant burning during or after sexual intercourse.
• Itching: While common, the burning sensation usually outweighs the itch in cases of CV.

Medical researchers are still investigating exactly why some women develop an overgrowth of Lactobacilli while others do not. However, several factors appear to contribute to the environment that fosters CV. These include high levels of glycogen in the vaginal tissues, which can be linked to hormonal shifts, and an environment that is already naturally acidic.

There is also some evidence that the overuse of probiotics or 'vaginal health' supplements containing certain Lactobacillus strains might contribute to the issue in susceptible individuals. Unlike Bacterial Vaginosis (BV), which is marked by a lack of these bacteria and a high pH, CV is the exact opposite—too much of a good thing.

CV vs Thrush

Thrush is caused by a fungus (Candida). CV is caused by bacteria. If you have been treated for thrush multiple times with fluconazole or clotrimazole and your symptoms persist—or if a vaginal swab comes back negative for fungus despite your symptoms—it is time to consider CV.

CV vs Bacterial Vaginosis (BV)

BV usually involves a 'fishy' odour and a high pH (above 4.5). CV has a very low pH and usually no strong odour, or a slightly sour smell. In the UK, NICE guidelines for managing vaginal discharge often focus on screening for STIs, thrush, and BV first, meaning CV is often only diagnosed after these have been ruled out.

The primary goal of treating cytolytic vaginosis is to raise the vaginal pH back to a healthy range (4.0 to 4.5). Unlike most infections, CV is not treated with antibiotics or anti-fungals. Instead, management focuses on alkalising the environment.

• Sodium Bicarbonate Baths: Sitting in a shallow bath (sitz bath) with a small amount of household bicarbonate of soda once or twice a week is often recommended.
• Alkaline Douches: While douching is generally discouraged in the UK for general hygiene, a medically advised, weak bicarbonate of soda solution may be used for a short period to neutralise acidity.
• Menstrual Management: Some patients find that using tampons can help by absorbing the acidic discharge, or that the alkalinity of menstrual blood provides temporary relief.
• Avoiding Low-pH Products: Patients should stay away from commercial 'vaginal washes' or lubricants that are designed to be highly acidic.

If you have persistent vaginal discomfort that has not responded to standard treatments, it is essential to speak to a healthcare professional. You can speak to an online doctor in the UK to discuss your symptoms in a confidential environment. This is particularly useful if you have already seen a pharmacist and used thrush treatments without success.

An online consultation allows you to provide a detailed history of your symptoms, their relation to your period, and your treatment history. While a definitive diagnosis of CV often requires a microscope to see 'clue cells' and fragmented epithelial cells, a GP can help rule out other causes such as STIs or aerobic vaginitis and guide you on the safe use of alkalising treatments.