Vaginal candidiasis (thrush) – symptoms and treatment

Definition of the disease. Causes of the disease

Vaginal candidiasis (candidal vaginitis) is the inflammation of the vaginal mucosa caused by yeast-like fungi of the genus Candida. This condition is commonly referred to as thrush.

In recent years, there has been an increase in candidiasis caused by other species of the Candida genus. The most commonly identified species include:

  • C. glabrata (15%);
  • C. dubliniensis (6%);
  • C. tropicalis (3-5%);
  • C. parapsilosis (3%);
  • C. krucei (1-3%).
    The spread of new microbial species is primarily associated with uncontrolled self-treatment by patients, leading to increased resistance of fungi to medications.
    The frequency of candidal vaginitis among vaginal and vulvar infections is 30-45%. It ranks second among all vaginal infections and is a common reason for women to seek medical help. According to J.S. Bingham (1999):
  • By age 25, about 50% of women of reproductive age have experienced at least one diagnosed episode of vaginal candidiasis;
  • By the onset of menopause, around 75% have experienced it.
    Candidal vaginitis is rarely observed in postmenopausal women, except for those receiving hormone replacement therapy.

Predisposing factors for the disease include:

  1. Mechanical factors – wearing synthetic underwear, first sexual intercourse, traumatic injury to the vaginal tissues, prolonged use of intrauterine devices.
  2. Physiological factors – pregnancy, menstruation.
  3. Endocrine factors – hypothyroidism, diabetes mellitus.
  4. Immunodeficiency states.
  5. Iatrogenic factors (use of antibiotics, corticosteroids, immunosuppressants, radiation therapy, chemotherapy, oncological diseases, oral contraceptives).
  6. Others (avitaminosis, allergic diseases, chronic pathologies of the genital and gastrointestinal tracts).
    The disease is usually not transmitted sexually, but it is established that it is associated with the nature of sexual contacts: anogenital and oro-genital. There is also a possibility of developing candidal balanoposthitis in sexual partners of patients with vaginal candidiasis.

Symptoms of vaginal candidiasis
The main symptoms of vaginal candidiasis include:

  • Burning and itching in the vaginal and vulvar area;
  • Curd-like discharge from the vagina;
  • Urinary disturbances;
  • Pain during sexual intercourse.

Itching may worsen after water procedures, sexual intercourse, at night during sleep, and during menstruation.
Overall, the symptoms of vaginal candidiasis worsen before menstruation. During pregnancy, the manifestation of the disease is also aggravated due to the decreased immunity in pregnant women.
Objective signs of vaginal candidiasis include:

  • Swelling and hyperemia of the vaginal mucosa and external genitalia;
  • White or greenish-white deposits on the walls of the vagina;
  • Redness of the vaginal mucosa.
    In complicated candidiasis, vesicles may appear on the skin of the external genitalia – blisters that rise above the level of the skin or mucous membrane and are filled with transparent or cloudy contents, which may rupture and form erosions. Cracks in the vulvar mucosa, posterior commissure, and perianal area may also be observed in vaginal candidiasis.

Pathogenesis of vaginal candidiasis

Fungi of the genus Candida belong to the opportunistic microflora, which is present in both the environment and on the surface of healthy human skin and mucous membranes (in the oral cavity, intestines, vagina). When the body’s defense mechanisms are compromised, there may be an increase in the adhesive properties of the fungi, allowing them to adhere to the epithelial cells of the vagina, colonize the mucous membrane, and trigger an inflammatory response.

Vaginal candidiasis often affects only the superficial layers of the vaginal epithelium without penetrating deeper layers of the mucous membrane. However, in rare cases, the epithelial barrier is breached, leading to invasion into the underlying tissue and subsequent hematogenous dissemination (spread of the infection agent from the primary focus of the disease throughout the organ or body via the bloodstream).

The main stages of pathogenesis include:

  1. Adhesion of fungi to the mucous membrane and colonization.
  2. Invasion into the epithelium.
  3. Overcoming the epithelial barrier.
  4. Penetration into the connective tissue.
  5. Overcoming tissue’s defense mechanisms.
  6. Entry into blood vessels.
  7. Hematogenous dissemination.

In vaginal candidiasis, inflammation occurs in the upper layers of the vaginal epithelium. This is because there is a dynamic balance between the fungus, which cannot penetrate deeper layers, and the body, which restrains its spread. Consequently, the infection may persist in one location for an extended period, manifesting as curd-like vaginal discharge. Disease exacerbation occurs when there is a shift in the balance between fungal growth and the body’s defense mechanisms.

Classification and stages of development of vaginal candidiasis

According to national clinical recommendations, two forms of vaginal candidiasis are distinguished:

  • Acute – up to three exacerbations per year;
  • Chronic (recurrent) – at least four exacerbations per year.

According to the classification proposed by D.A. Eschenbach, vaginal candidiasis is divided into two types:

  • Uncomplicated;
  • Complicated.

In women, three forms of the disease are distinguished:

  • Vaginitis (inflammation of the vagina);
  • Vulvovaginitis (inflammation of the vagina and vulva);
  • Cervicitis (inflammation of the cervix).

In men, the following forms are distinguished:

  • Balanitis (inflammation of the glans penis);
  • Balanoposthitis (inflammation of the foreskin and glans penis);
  • Urethritis (inflammation of the urethra).

The acute form of vaginal candidiasis is characterized by pronounced symptoms: abundant vaginal discharge, burning, and itching in the vagina and external genitalia. These symptoms often lead to decreased productivity in patients and the development of neuroses. The acute form of vaginal candidiasis is most common and develops due to an increase in the number of Candida fungi in the vagina against the background of decreased patient immunity.

Recurrent vaginal candidiasis occurs in 10-15% of women of reproductive age and is characterized by four or more exacerbations per year.

The uncomplicated form of the disease involves the first occurrence or less than four occurrences per year of vaginal candidiasis with moderate manifestations of vaginitis in patients without accompanying risk factors (diabetes mellitus, use of glucocorticoids, cytostatics, etc.).

In complicated vaginal candidiasis, vivid objective symptoms are observed: redness, swelling, ulcer formation, cracks in the mucous membranes, and skin of the perianal area. Recurrences four or more times a year are also typical. The disease often occurs against the background of diabetes mellitus, HIV infection, glucocorticoid and cytostatic therapy. The causative agents in this case can be both C. albicans and other fungi of the Candida genus.

Complications of vaginal candidiasis in women include:

  • Vaginal stenosis: develops when the walls of the vagina become inflamed, causing narrowing of the vaginal canal and decreased elasticity. Patients experience pain during sexual intercourse.
  • Inflammatory pathologies of the pelvic organs such as salpingitis (inflammation of the fallopian tubes), oophoritis (inflammation of the ovaries), and others.
  • Urinary tract diseases such as cystitis (inflammation of the bladder) and urethritis (inflammation of the urethra).

Vaginal stenosis occurs due to inflammation of the vaginal walls, leading to narrowing of the vaginal canal and reduced elasticity. Patients experience pain during sexual intercourse.

Salpingitis is an infectious-inflammatory disease of the fallopian tubes. It occurs when the infection ascends from the vagina, although hematogenous transmission is also possible. Salpingitis often occurs in combination with oophoritis – inflammation of the ovaries. Patients experience pain in the area of the appendages, lower abdominal pain on the left or right side, fever, malaise, weakness, and sometimes nausea with vomiting. Untreated salpingitis can lead to infertility, ectopic pregnancy, adhesion formation requiring surgical intervention, infection of the abdominal and pelvic organs. Salpingitis is particularly dangerous when combined with other infections.

Urethritis is inflammation of the urethral mucosa. It manifests as painful urination, burning sensation in the urethral area, blood or pus in the urine, discomfort when in contact with clothing, sticking of the edges of the urethra, and redness around the urethral opening.

Cystitis is inflammation of the bladder. The pathology occurs when the infectious agent enters the bladder ascending through the urethra. The symptoms of cystitis are similar to those of urethritis, but there are some differences: frequent urination with a small amount of urine, feeling of incomplete emptying of the bladder, pain, burning at the end of urination, cloudy urine, fever, lower abdominal pain.

Vaginal candidiasis increases the frequency of complications during pregnancy and the risk of fetal infection. Candidiasis in the fetus can lead to intrauterine death or premature birth. After childbirth, women may develop candidal endometritis – inflammatory processes in the tissues lining the inner cavity of the uterus.

Diagnosing vaginal candidiasis relies on characteristic patient complaints, medical history, clinical manifestations observed during gynecological examination, such as erythema, swelling of the mucosa, and white plaques on the vaginal walls.

Confirmation of the diagnosis typically relies on laboratory data, including:

  1. Microscopy of vaginal discharge smears, which allows for the identification of fungal spores and hyphae.
  2. Culture method, involving the seeding of vaginal contents on nutrient media. This method determines the quantity and types of fungi, their susceptibility to antifungal agents, and the presence of other microorganisms.
  3. Serological diagnosis (RSK), which detects antibodies against antigens of Candida species, particularly in cases of systemic involvement.
  4. Molecular-biological methods, such as polymerase chain reaction (PCR), aimed at detecting specific DNA fragments of Candida spp.
  5. Immunofluorescence diagnosis (Candida Sure Test), used in cases of recurrent vaginal candidiasis.

Additional diagnostic methods may include studying the intestinal microbiota, screening for sexually transmitted infections, and intravenous glucose tolerance testing.

Differential diagnosis is conducted with the following conditions:

  • Genital herpes;
  • Bacterial vaginosis;
  • Aerobic vaginitis;
  • Skin diseases (eczema, red flat lichen, scleroderma, Behçet’s disease, etc.).

Treatment of vaginal candidiasis is indicated based on the patient’s complaints, clinical manifestations, and laboratory confirmation of Candida species presence. Treatment is not necessary when Candida species are detected without any clinical manifestations (carriage). This rule is because Candida species may be present in small amounts in the vagina and are part of the normal flora if their quantity does not exceed the threshold of 104.

The mechanism of action of antifungal drugs is the disruption of ergosterol synthesis (a substance in the cell membranes of fungi), leading to the formation of defects in the microorganism’s membrane. Depending on the dose, antifungals exhibit either fungistatic (slowing growth) or fungicidal (complete destruction) effects.

There are various groups of drugs for treating vaginal candidiasis:

  • Antibiotics (pimafucin, amphotericin B, nystatin, levorin);
  • Imidazoles (clotrimazole, sertaconazole, ketoconazole, gino-pevaril, miconazole);
  • Triazoles (itraconazole, fluconazole);
  • Combination drugs (“Terzhinan”, “Polygynax”, “Pimafucort”, “Cleon D”, “Macmiror complex”);
  • Drugs from different groups (flucytosine, griseofulvin, daphnedgin, nitrofungin, polyvinylpyrrolidone iodate).

Treatmen

Treatment is selected individually for each patient by a gynecologist, taking into account the clinical picture, the form of the disease, and the severity of symptoms. However, it is important to note that fluconazole is contraindicated in the treatment of vaginal candidiasis during pregnancy, as it may negatively affect fetal development.

For acute forms of vaginal candidiasis, local treatment is prescribed. The drug is not absorbed into the systemic circulation but acts in the area of the vagina and mucous membrane. Examples of treatment regimens:

  • Econazole 150 mg in the form of vaginal suppositories once daily for three days;
  • “Clindacin B prolong” one applicator of cream at night vaginally for three days;
  • “Macmiror complex” one suppository at night once daily for eight days;
  • “Terzhinan” one tablet at night for 10 days.

For chronic candidiasis, systemic antifungals are used in addition to local treatment:

  • Fluconazole 150 mg orally once;
  • Itraconazole 200 mg orally twice with a 12-hour interval for one day or 200 mg daily for three days.

For recurrent forms of the disease (more than four episodes per year), the following scheme is used:

  • Fluconazole 150 mg orally three times with a 72-hour interval on days 1, 4, and 7 of treatment.

To prevent recurrences, the drug is administered at a dosage of 150 mg once weekly for six months.

In recent years, there has been increasing research on the ability of C. albicans to form biofilms—substances on the surface of microorganism colonies that serve as a barrier to the penetration of drugs and ensure survival. The main polysaccharide determining resistance to antibiotics is glucan. It is considered one of the reasons for the development of resistance to antifungal drugs. This explains the lack of effect in treatment in some patients. For such patients, feniconazole 600 mg once daily with a three-day interval may be recommended. The drug differs from others in its ability to overcome biofilms, thereby increasing the effectiveness of treatment for resistance to other drugs.