Candidiasis, also known as yeast infection or thrush, is a disease caused by a species of fungus of the Candida genus (most commonly the etiologic factor is Candida albicans). It can have different manifestations and symptoms, ranging from mild to serious, possibly life threatening. While the mild form is in most of the cases an expression of a disequilibrium in the normal flora of a region of the body (after use of antibiotics, in pregnant women or those using contraceptive medication, in cases of endocrine disorders etc.) and can be easily treated, the severe forms are recurrent, appear in immunocompromised patients (suffering of a disease such HIV infection, AIDS, malignancies or undergoing radiation or chemotherapy).

Pathogenic Candida species (such as Candida albicans) adhere to epithelial and mucous layers of the tissues because they have affinity for the components of the cellular wall, causing local inflammatory manifestations and discomfort, colonize the area and then multiply, appearing as psudofilaments when examined under microscope. The most frequent clinical forms encountered are:

1. Oral and perioral form: the infection can be localized at the level of the oral cavity mucous membrane or it can advance in the pharynx or esophagus. The mucous membrane is red, eritematous, with white or grey deposits or patches at this level. The tongue can be smooth, depapilated or it can present the same white patches with a “hairy” aspect. These lesions of the tongue can lead to various symptoms, such as pain, itching, soreness or burning sensation. In immunocompetent persons, the infection is localized and will not extend. In immunosupressed persons, the fungus can later pass through the cellular wall, invade the capillaries, causing fungal septicemia or candidemia, which is a very serious and hard to treat condition.
2. Genital form: represent perhaps the most frequent affection encountered in gynecological services. Statistics have shown that approximately 90% of women have during their lifetime at least one vaginitis caused by infection with Candida. This vaginitis is not associated with sexual activity in most of the cases, it can appear in virgin women too, and is most likely related to use of antibiotics. In many cases, candidiasis can be associated with another vaginal pathology, such as infections with gram+ or gram– bacteria ( Gardnerella vaginalis, Chlamydia, E. Coli, Klebsiella etc.) or parasites (Trichomonas vaginalis). Candidiasis affects the region of the vulva ( in acute cases), as well as the vagina (in chronic cases, frequently after repeated episodes of infection ). The main symptoms is represented by white vaginal discharge associated with colpitis (inflammation of the vagina). Normally, the vagina has a physiologic discharge which represents the secretion of the glands in the region around the vulva and inside the vagina. This normal discharge has a whitish color, nonspecific smell and its quantity and aspect vary during the menstrual cycle. In the case of candidiasis, the discharge modifies its characteristics, is very abounded (range from liquid white discharge to thick discharge, which has the appearance of “cottage cheese”), has a specific smell and is accompanied by other symptoms, usually itching sensation (can be very disturbing and persistent), burning-like sensation, pain during intercourse, redness in the region around the vulva, painful urinations (Candida can also provoke urinal infections associated with vaginitis). Although candidiasis is not a sexual transmitted disease, it can appear in men after a sexual contact with an infected partner. Symptoms are represented by red patches on the head of the penis, a white secretion which appears usually in the morning, intense burning and itching sensation. Treatment must be given to both partners, because incorrectly treated it can cause reinfections.
3. Coetaneous form: are characterized by appearance and development of eritematous patches, sometimes associated with vesicles full of puss (in case of bacterial infection). Anyway, in most of the cases the lesions are localized and don't extend to the near areas.
4. Generalized form: appear in immunosupressed patients, after recurrent infections and are possibly life-threatening. Are very difficult to treat, because in most of the cases the fungus in resistant to medication and the organism doesn't have enough resources to defend itself. There have been reported a few cases of candidal meningitis and endocarditis in patients with terminal AIDS.