Thrush or candida as it is otherwise known, is one of the main side effects or antibiotic or antimicrobial treatments for chronic UTI. The good news is that healthy bacteria in your gut and vagina can help to keep candida levels in check.
Why do antibiotics cause thrush?
Antibiotics can upset the gut or vaginal microbiome which may lead to the overgrowth of abnormal microbes or fungi such as bacteria or candida in the gastrointestinal tract.
Candida is an opportunistic fungus that is present in the human body normally. Probiotic bacteria that live in the gut and in other parts of the body keep the fungi from becoming a problem. Some strains of bacteria excrete anti-fungal chemicals while others provide a barrier between the gut walls and the candida spores.
Candida becomes a problem when the probiotic bacteria, the natural ‘regulators’ in the gut microbiome, are compromised.
As well as antibiotic or antimicrobial treatments these factors can make candida/thrush more likely:
- Eating a diet high in refined carbohydrates and sugar
- Taking oral contraceptives or using an IUD device
- Suppression of the immune system through long-term health problems
Thrush can affect anyone, though it occurs most in babies, toddlers and older adults. Left untreated fungal infections can spread to other parts of the body.
How candida grows
The candida cells, which are relatively benign in their yeast form, adopt their fungal form and begin to grow hyphae – the long branches that grow out of the fungus. These branches invade the cells in your intestinal lining and creating inflammation.
Vaginal flora and pH levels
A healthy vaginal flora protects the body against urogenital infections. It is made up of many different types of probiotic bacteria, the predominant bacteria being lactobacilli. Indeed, these lactobacilli and candida species often co‐exist in the vagina of healthy women.
Lactobacilli protect against vaginal infection simply by colonizing the space available. They build up a barrier against candidal overgrowth by blocking the adhesion of candidal yeast cells to vaginal epithelial cells, through competition for nutrients. They also produce lactic acid and hydrogen peroxide. Lactic acid helps to maintain a healthy vaginal pH and flora. Hydrogen peroxide stops the overgrowth of ‘bad’ bacteria that cause infection. When the level of lactobacilli is disrupted and the vaginal flora becomes imbalanced, the risk of developing an infection is increased. The infections can lead to unpleasant symptoms such as itching, irritation, burning, abnormal discharge and unpleasant vaginal odour.
The balance between beneficial and harmful bacteria in the vagina is very fragile, an imbalance occurs if the vaginal pH is not acidic enough. The vagina pH should be somewhere between 3.8 and 4.5 for a healthy level of vaginal acidity. If the vagina is not acidic enough due to a shortage of lactobacilli, then fungi and ‘bad’ bacteria are able to reproduce more than they usually would.
Antibiotic treatment for a UTI can affect the vaginal flora. Two examples of infection that arise in this way are thrush (caused by overgrowth of the fungus Candida) and bacterial vaginosis (caused by overgrowth of ‘bad’ bacteria).
The role of oestrogen
Interestingly, oestrogen levels are important for the maintenance of vaginal pH. Thrush spores are noted to be at their highest during the latter half of a women’s monthly cycle when oestrogen levels are lower because the vaginal pH balance has become more alkaline. Thrush can affect women on low oestrogen birth control or when they enter peri, menopause or become post menopausal. This is again because of the loss of oestrogen.
Localised oestrogen therapy can help restore levels within the vagina and may help with the control of outbreaks of thrush.
However, too much oestrogen may encourage candida cells to multiply. A study published in the American Society of Microbiology in 2006 found, if certain types of oestradiol (a specific type of oestrogen found in birth control pills or hormone replacement therapies) are added to candida cells, this oestrogen has been shown to increase the number of germ tube and length – developments that support candida overgrowth.
Oestrogen also acts on Candida yeasts and promotes its growth, and improves its ability to cling onto vaginal epithelial cells as shown by this study published in PLoS Pathogens in 2014.
These changes together may encourage the overgrowth of Candida, and further studies are being conducted to gain a better understanding of these mechanisms.
What are the symptoms of vulval/vaginal thrush?
- Vulval itching
- Vulval soreness, burning or irritation
- Pain, or discomfort, during sexual intercourse (superficial dyspareunia)
- Pain, or discomfort, during urination (dysuria)
- Vaginal discharge – although this is not always present. The discharge is usually odourless and can be a thin, watery fluid, or thicker, white, and a similar texture to cottage cheese.
- Vulvovaginal inflammation
- Erythema or redness of the vagina and vulva
- Vaginal fissuring (cracked skin) – in severe cases
Types of candida species
Of the 150-plus species of fungal Candida, the most commons fungal species are:
- candida albicans
- candida krusei
- candida glabrata
- candida parapsilosis
- candida tropicalis
Candida in the bladder
The use of catheters, instruments in the urinary tract either during surgery or after as well as antibiotic therapy may also cause candida UTI. Biofilm is critical to candidal growth on devices, such as urinary catheters that are latex coated with silicone which allows the biofilm to attach and develop. This biofilm encourages fungal spores to attach and develop fungal communities.
Fungal infections can cause a lot of pain because they grow and send out tentacles that latch into the bladder wall disrupting the sensitive nerve endings within the urinary tract. Cystitis symptoms or a UTI due to an upsurge of candida may result in frequency, urgency, pain on urination and supra-pubic pain. You may often have blood in the urine as well if the vulval/vaginal skin is cracked and bleeding.
Testing for thrush
Where to get tested
GP surgeries and sexual health clinics can swab for thrush. If you’re struggling with thrush and your GP has offered no assistance then the local walk-in GUM (genito urinary medicine) clinic can help. They have staff used to treating patients discretely and confidentially with possible thrush or other vulval vaginal infections such as Bacterial vaginosis (BV) or sexually transmitted diseases/infections (STDs/STIs). They will swab and analyse under the microscope. On diagnosis, they will prescribe a suitable course of treatment.
But not all clinics will offer sensitivity testing – detailed analysis of the candida strain to identify it and any anti-fungal susceptibilities. Sadly cuts to national health budgets are limiting the services that can be offered by these clinics. You may have to consider testing via a private clinic.
Keep on getting thrush or it doesn’t seem to go away?
If thrush persists, ask the GP for a referral to your local hospital vulval clinic. These offer specialist services dealing with issues affecting the vagina and vulva including chronic candidiasis. As well as examining you, a detailed swab will be taken and analysed in laboratory. This will determine the strain of thrush and its susceptibilities or resistances and they can prescribe the correct treatment from there.
Invivo – Vaginal Ecologix (available through a clinical practitioner only)
Evvy – The Evvy Vaginal Microbiome Test can ordered directly from their webpage (only available currently to US residents. They do not ship internationally).
Juno – The Juno Bio vaginal microbiome test is available globally and can be ordered from their webpage.
Systems Biology Laboratory – The Vaginal Microbiome test is available to UK mainland residents only and can be ordered from their webpage.
What to know before you get tested
Thrush is hard to culture and false-negatives are common, previous anti-fungal treatment can also affect results. Thrush spores are at their highest the week leading up to menstruation and during menses due to the alkaline changes in the vaginal tract. Menstrual blood is itself alkaline so the best time to be tested is either just before your period or shortly after it has finished.
Don’t take or use any oral or topical anti-fungal treatments 7-10 days before the test otherwise this will affect the result and you could get a false negative result.
Is it actually thrush?
The following can also cause similar symptoms to thrush and you should seek early diagnosis and appropriate treatment.
- Bacterial Vaginosis (BV) or Gardnerella vaginalis
- Lichen Sclerosus
- Group B Streptococcus
- Mycoplasma hominis and Mycoplasma Genitalium
- Cytolytic Vaginosis
- Aerobic Vaginitis
Treatments for thrush
Fluconazole tablets can be purchased over the counter in any pharmacy or prescribed by the GP. They can be taken either as a single dose or for longer under the guidance of a GP or physician.
Prescription oral anti fungal medication
Both Fluconazole and Itraconazole can be prescribed. Be aware that these medications are contra-indicated against Warfarin and should not be taken if using statins, antibiotics classed as macrolides, SSRI antidepressants or medications for irregular heart beat. Always discuss existing medications, possible contra-indications, recommended dosage and length of usage with your practitioner or GP.
If taking oral fungal medications, it is recommended that liver function is checked regularly via a GP blood test. This is particularly important for those taking oral medications for longer than four weeks. Oral anti-fungals can affect liver function.
Be aware that oral fungal medications work best in an acidic environment so if taking protein pump inhibitors (PPIs) for excess stomach acid, antacids or other stomach acid reducing medications, take oral fungal medications well away from these.
Another alternative treatment is to take Nystatin powder, this is usually prescribed by a doctor and can be taken orally if suffering systemic candida issues alongside vaginal candidasis. Note that Nystatin Powder is not suitable for the treatment of vaginal thrush.
Within the Multi-Gyn product range there is Multi-Gyn active gel (formerly known as Bio-fem active gel) for Bacterial Vaginosis and there is Multi-Gyn Floraplus for thrush. Both of these gels can be purchased over the counter from pharmacies or online.
Within the Salcura Natural Skin Therapy range Topida intimate topical spray has found favour with a number of Chronic UTI sufferers for helping to alleviate the symptoms of Thrush
The Chronic Urinary Tract Infection Campaign (CUTIC) has secured an affiliate partnership with the manufacturers of Topida Intimate Spray. They are kindly offering a 15% discount on everything purchased directly from their website. Just add the code CUTIC15 to your order. Please note this is applicable to UK and Eire customers only.
Clotrimazole or Canestan cream
Canesten is the branded product and also contains more of the active ingredient at 2%, but is more expensive. Clotrimazole only contains 1%. These can be purchased at any pharmacy or on prescription from the GP. If you have vulval vaginal issues please check if any additives may cause irritation before usage.
There are also intra-vaginal pessaries such as clotrimazole or canesten pessaries, econazole and miconazole. These work in a similar way to the cream, but can cause burning, vaginal dryness and further irritation to some, again use with caution if you are very sensitive.
Nystatin cream and pessaries
Vaginal candida cases related to non-candida albicans species can be treated by Nystatin intra-vaginal pessaries or cream — Nystatin is the only licensed alternative to azole therapy. Please note that in the UK at present it is unlicensed and would need to be purchased overseas.
The probiotic VSL3 can also be mixed with a small amount of water, just enough to make a paste and inserted in the vagina which can help to relieve and treat thrush.
Boric acid pessaries
Boric acid is a white, crystalline chemical substance that has anti-fungal and antiviral properties. It is used in various prescription pharmaceutical products and is also available without a prescription in some countries. Vaginal boric acid capsules are a treatment option for vaginal yeast infections, particularly infections that can’t be cured by anti-fungal yeast infection medicines. If you are pregnant, do not use vaginal boric acid treatment.
When used in capsules as a vaginal suppository, boric acid is known to sometimes cause skin irritation so again if vaginal or vulval tissues are sensitive please discuss with either a pharmacist or appropriate practitioner before purchasing for treatment. Be aware that if taken orally or used on an open wounds boric acid is toxic. Keep boric acid out of the reach of children.
How to apply topical medications
Apply a pea sized dose to those areas where the itching is most intense. Ensure that any application to the anal region is the last area treated to prevent any bacteria being transferred to the vulva and around the urethral entrance.
Probiotics, bacteria that are naturally occurring in the body, are often recommended as a treatment for vaginal flora imbalance. Probiotics can help to restore a healthy level of lactobacilli both in the gut and in the vulval-vaginal area particularly after a course of antibiotics. The vaginal flora of healthy premenopausal woman is generally dominated by a number of Lactobacillus species.
Because vaginal lactobacillus species produce lactic and hydrogen peroxide, maintaining the vaginal pH around 4.5 or less and hampering growth of pathogenic bacteria and fungi, they are thus considered protective against vulval vaginal candidiasis (VVC) and bacterial vaginosis (BV). This has increased the interest in the beneficial effect of Lactobacillus species-containing probiotics in restoring and maintaining the vaginal microbiome.
Are probiotics effective for long term vaginal health?
The effectiveness of probiotics for the treatment of VVC in non-pregnant women was evaluated in 2017 in a Cochrane systematic review. A total of 10 RCTs (1656 participants) investigating the effect of probiotics used by the oral and vaginal route as a complementary therapy to conventional antifungal drugs were included. Probiotics slightly improved the short-term clinical cure rate and reduced the 1-month relapse rate. However, no important impact of probiotic use was observed on long-term clinical cure rate (3-month post-treatment evaluation). Given the low- or very low-quality of the considered studies, the authors emphasized the need for further and better designed RCTs with larger sample size, standardized methodology for probiotic preparation, and longer follow-up. More studies are needed to conclude that taking probiotics orally or vaginally alone will inhibit vaginal candida overgrowth and successfully treat any fungal infections.
The use of probiotics in people who have a health condition of the bowel should always be discussed with their GP or consultant.
There are also particular risks associated with supplements that are meant to be taken vaginally. There is the risk of introducing other bacteria with insertion – for instance, because of dirty hands or if the tablet wasn’t clean at insertion – as well as the risk of small cuts in the vagina if it’s not inserted correctly and the risk of increased vaginal discharge and change in odour.
There is also the question of cost – both vaginal and oral probiotic supplementation can be expensive. Your gynaecologist, genito urinary medicine doctor or women’s health doctor should advise as to whether their usage is necessary.
If the vaginal PH is too alkaline, lactic acid pessaries are also available.
Eating the right diet to prevent thrush
To prevent thrush consider limiting your sugar and refined carbohydrate intake. Any change in diet must be tailored to your individual circumstances. A good starting point is to firstly look at your lifestyle and your budget and what dietary changes are possible based on these factors. We all know that a healthy diet encourages eating plenty of fruit, vegetables, healthy fats, lean protein, and other plant-based foods.
You may also wish to consider the following to manage candida infections on a day to day basis:
- Switch to cotton or silk underwear from synthetic fabrics. Wearing underwear that doesn’t breathe can raise body heat and moisture in the vagina. This creates conditions for yeast spores to grow.
- Change out of swimsuits and workout clothes as soon as possible if they are made of synthetic materials. Ideally switch to predominantly cotton based brands.
- If possible try to wear joggers or go underwear free when at home. Tight jeans prevent air circulation and again can encourage thrush spores to multiply. You also risk chafing of already sore and inflamed vulval skin.
- Avoid removing all pubic hair. The Royal College of Obstetricians and Gynaecologists advises that having at least some pubic hair is important as it forms a natural barrier between your skin and bacteria. Removing it by shaving actually irritates the skin – leaving the area much more prone to infections such as thrush.
- Launder your underwear in hot water and consider adding an anti-bacterial cleaner to your laundry powder or liquid. This temperature is important as it needs to be effective in killing yeast microbes. Dry clothing using the hottest setting of the dryer, or air-dry in bright sunlight.
- Avoid soaps, foam bath, bath salts, deodorants or talcum powder in the genital area.
- Don’t use deodorised panty liners or vaginal douches which can upset vaginal PH and remove beneficial vaginal microbes.
- Use a water-based lubricant during intercourse and avoid spermicidal condoms.
- Shower after exercising and only wash your vulva with water. Always dry the vulval area and pelvic area including the creases at the top of the thighs, any moisture can encourage fungal spore growth.
- A bicarbonate of soda bath may help soothe and relieve yeast infection symptoms and may help to regulate vaginal pH. A 2014 study published in Current Microbiology found that bicarbonate of soda killed Candida cells that lead to yeast infections. It has also been found to have general antifungal affects through a study published in 2013 in Mycopathologia.
Human blood is comparatively alkaline, with a pH of around 7.35 – 7.45. During menstruation, the presence of blood in the vagina raises the vaginal pH above normal, disrupting the usual environment, and favouring the growth of Candida. With tampons resting in the vaginal tract and no immediate outlet for the menstrual flow, for some this can alter PH levels leading to an upsurge of candida or bacterial vaginosis during or shortly after menstruation has finished. Tampons can also be drying on the vaginal tract.
Try using unscented sanitary towels as the bleach, scent and plastic in most high street and brand name sanitary towels can irritate vulval and vaginal tissue for some people. The following are recommended:
Alternatively Boots and Sainsbury’s in the UK sell their own branded sanitary protection that is unscented. These products are much cheaper than Natracare or Time of the Month but they are still bleached and contain plastics. However the major irritant – the scent – has been removed.
We explain how probiotics may help to repopulate the gut with healthy bacteria.
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