Vaginal thrush or candidiasis is an overgrowth of yeast leading to an infection of the vagina, sometimes also affecting the surrounding areas such as vulva. It is known as candidiasis because of the causative yeast Candida albicans. These yeasts are often naturally occurring on the human body but is kept in check by various factors. Vaginal thrush is very common in women usually in their 30s and 40s and in pregnant women. It can be treated but often recurs because the contributing factors to yeast overgrowth persists.
- Isolated: Occurs now and then once off but may return years later.
- Relapsed: Return of infection within a few weeks, usually due to inadequate treatment.
- Resistant: Rare forms of candidiasis which is refractory to treatment.
- Recurrent: Four or more episodes per year.
Some woman may not have symptoms and may be diagnosed with vaginal thrush during a routine examination or on cervical smear tests. Symptoms of vaginal thrush include:
- Itching of the vulva with soreness and irritation.
- Creamy white vaginal discharge, usually odorless.
- Redness of the vagina and vulva.
- Pain or discomfort during sex and urination.
Candida albicans is the most common organism causing vaginal thrush in almost 80% of the cases. Normally the bacterial flora in the vagina provides protection against fungal infections and developing vaginal thrush by preventing yeast overgrowth. Vaginal thrush develops if the candida infection multiplies excessively beyond the control of the bacterial flora. Antibiotics which destroy the normal bacterial flora can put a person at risk of candida infection.
High levels of estrogen as usually seen during pregnancy can cause excessive growth of fungus. Estrogen containing oral contraceptives can have the same effect on the vaginal mucosa. The disease is more common in the immunocompromised patients as in HIV patients and in patients receiving drugs preventing organ rejection, steroids or chemotherapy. Use of urinary catheters can also put a person at risk of candidiasis.
Yeast infections are usually self limiting. Over-the-counter and prescription antifungal agents such as clotrimazole, butoconazole, miconazole and tioconazole can be helpful. These medications are applied topically in and around the vagina. In pregnancy these drugs are to be used under medical supervision. Vaginal swab helps in isolation of the causative organism and diagnosis. Medical treatment of candidiasis can be in the form of creams, lotions, pills or vaginal suppositories.
The azole group of drugs kills the yeasts by preventing ergosterol and essential element of the yeast cell wall causing the cell wall to rupture. Nystatin and amphotericin B (polyene antifungals) are the higher drugs or choice and are usually reserved for use in advanced stages of yeast infection such as when there could be systemic spread of the infection. These drugs also act by rupturing or creating holes in the cell wall of the fungi.
Most candida vaginal infections go away within one to two weeks. The infection is recurrent in patients with weakened immune system and is usually difficult to treat. Certain medications used in candidiasis can weaken the latex in condoms and vaginal diaphragm and may provide inadequate contraception. Use of such contraceptive means is not reliable during treatment of vaginal thrush. Yeast infections can be prevented by adding antifungal medications to antibiotics during antibiotic treatment.