Candidiasis

Candidiasis
Specialty	Infectious diseases, dermatology

Candidiasis, commonly called yeast infection or thrush, is a fungal infection of any of the Candida species, of which Candida albicans is the most common.

Manifestation

In immunocompetent people, candidiasis can usually only be found in exposed and moist parts of the body, such as:

• the oral cavity (oral thrush)
• the vagina and/or vulva (vaginal candidiasis or thrush)
• folds of skin in the diaper area (diaper rash)
• the nipples while breastfeeding

Candidiasis is the second most common cause of vaginal irritation, or vaginitis, and can also occur on the male genitals, particularly in uncircumcised men. In immunocompromised patients, the Candida infection can involve the esophagus and can become systemic, causing a much more serious condition: fungemia.

Children, mostly between the ages of 3 and 9 years, can be affected by chronic mouth yeast infections, normally seen around the mouth as white patches. However, this is not a common condition.

Causes

Yeast organisms are always present in all people, but are usually prevented from "overgrowth" (uncontrolled multiplication resulting in symptoms) by naturally occurring microorganisms.

At least three quarters of all women will experience candidiasis at some point in their lives. The Candida albicans organism is found in the vaginas of almost all women and normally causes no problems. However, when it gets out of balance with the other "normal flora," such as lactobacilli (which can also be harmed by using douches), an overgrowth of yeast can result in noticeable symptoms. Pregnancy, the use of oral contraceptives, engaging in vaginal sex after anal sex in an unhygienic manner, and using lubricants containing glycerine have been found to be causally related to yeast infections. Diabetes mellitus and the use of antibiotics are also linked to an increased incidence of yeast infections. Candidiasis can be sexually transmitted between partners. Diet has been found to be the cause in some animals. Hormone Replacement Therapy and Infertility Treatment may be factors.

Symptoms

Symptoms include severe itching, burning, and soreness, irritation of the vagina and/or vulva, and a whitish or whitish-gray discharge.

Many women mistake the symptoms of the more common bacterial vaginosis for a yeast infection. In a 2002 study published in the Journal of Obstetrics and Gynecology, only 33 percent of women who were self treating for a yeast infection actually had a yeast infection. Instead they had either bacterial vaginosis or a mixed-type infection.

In men, symptoms include red patchy sores near the head of the penis or on the foreskin. The sores may feel irritated and itchy, and sometimes they will burn as well.

Diagnosis

Medical professionals use two primary methods to diagnose yeast infections: microscopic examination, and culturing.

For the microscope method, a scraping or swab of the affected area is placed on a microscope slide. A single drop of 10% potassium hydroxide (KOH) solution is then also placed on the slide. The KOH dissolves the skin cells but leaves the Candida untouched, so that when the slide is viewed under a microscope, the hyphae and pseudo spores of Candida are visible. Their presence in large numbers strongly suggests a yeast infection.

For the culturing method, a sterile swab is rubbed on the infected skin surface. The swab is then rubbed across a culture medium. The medium is incubated for several days, during which time colonies of yeast and/or bacteria develop. The characteristics of the colonies provide a presumptive diagnosis of the organism causing symptoms.

Treatment

It is important to consider that Candida is part of the human body's normal oral and intestinal flora (although Candida is not a part of the normal flora of the skin) and an infection is more a "bloom" than the work of a parasite, as in the case of some bacterial infections. Despite this, Candidiasis is sometimes misdiagnosed by medical personnel as bacterial in nature, and treated with antibiotics. This can lead to eliminating the yeast's natural competitors for resources, and increase the severity of the condition.

Candidiasis can allegedly be successfully treated either with home remedies or, in the case of a more severe infection, with either over-the-counter substances or prescription antifungal medications. Home remedies for candidiasis include the consumption or direct application of yogurt, which contains lactobacillus, probiotics, acidophilus tablets or salves, and even lightly crushed cloves of garlic, which yield allicin, an antifungal agent. Boric acid has also been used to treat yeast infections (by inserting gelcaps filled with boric acid powder into the vagina at bedtime for three to four consecutive nights). Eating a diet consisting primarily of green, fresh, raw vegetables also may give relief.

While home remedies may offer relief in minor cases of infection (although a peer-reviewed study in Australia found yogurt ineffective as treatment for Candida albicans), seeking medical attention may be necessary, because the extent of the infection at times cannot be judged accurately by the sufferer. For instance, oral thrush is visible only at the beginning of the digestive tract, but it may be that more of the digestive tract is compromised by Candidiasis.

Prescription medication is often the only solution to an infection; the antifungal drugs commonly used to treat candidiasis are topical clotrimazole, topical nystatin, fluconazole, and topical ketoconazole. In severe infections (generally in hospitalized patients), amphotericin B, caspofungin, or voriconazole may be used. (These medications are not effective against the more common bacterial vaginosis.) Local treatment may include vaginal suppositories or medicated douches. Gentian violet can be used for breastfeeding thrush, but only as a last resort, since it can also cause mouth and throat ulcerations in nursing babies, and has been linked to cancer.

Treating Candidiasis solely with medication may not give desired results. If indicated, underlying causes should be considered. As an example, oral candidiasis is often linked to the use of inhaled corticosteroids in asthma medication. Patients on long-term inhaled corticosteroids should rinse their mouths after each dose of steroids to counterract this effect. Oral candidiasis can also be the first sign of a more serious condition, such as HIV. Following the health tips at vulvovaginal health can help prevent vaginal candidiasis. Babies with diaper rash should have their diaper areas kept clean, dry, and exposed to air as much as possible. Sugar assists the overgrowth of yeast; thus, the increased prevalence of yeast infections in patients with diabetes mellitus, as noted above. In the case of frequent yeast infections, sugar should be avoided. Breast milk also feeds yeast, and both a nursing mother and baby need to be treated (even if both are not symptomatic) to prevent thrush from being passed between mother and child.

As Candida spp. originates in the gut, some control may be exerted during an infection (and prior to or between infections) to prevent outbreaks. The fungus requires processed starches such as gluten, as well as sugars, to thrive. Dairy products and fermented foods may also contribute to its growth. As such, avoiding glutens, sugars, dairy products, and fermented foods (termed an "avoidance diet" by some practitioners, and by others as the "Candida control diet") may help to prevent overgrowth of the organism. It is important to remember that sugars include sucrose (common sugar), fructose, lactose, maltose, dextrose, and others (almost any food additive that ends in the letters "ose"), including maltodextrin. All of these types of sugars may contribute to Candidiasis, and may give relief if avoided. Additionally, increased water consumption may reduce fermentation opportunities in the gut.

Better treatment of Candidiasis may impact miscarriage rates.

History and taxonomic classification

B. Lagenbeck in 1839 in Germany was the first to demonstrate a yeastlike fungus in thrush. He also found that a fungus was able to cause thrush, a human oral infection.

The genera Candida, species albicans was described by Christine Marie Berkhout. She described the fungus in her doctoral thesis, at the University of Utrecht in 1923. Over the years the classification of the genera and species has evolved. Obsolete names for this genus include Mycotorula and Torulopsis. The species has also been known in the past as Monilia albicans and Oidium albicans. The current classification is nomen conservandum, which means the name is authorized for use by the International Botanical Congress (IBC).

The full current classification is available at Candida albicans.

The genus Candida includes about 150 different species. However, only about six are considered as causing human infections. C. albicans is the most significant species. Other species responsible for human disease include C. tropicalis, C. glabrata, C. krusei, C. parapsilosis, and C. lusitaniae.

Alternative views

Alternative medicine proponents also frequently diagnose people with "systemic candidiasis" using methods not deemed valid by mainstream, western medicine. This belief originated from a book published by Dr. William Crook which hypothesized that a variety of common symptoms such as fatigue, PMS, sexual dysfunction, asthma, psoriasis, digestive and urinary problems, multiple sclerosis, and muscle pain, could be caused by subclinical infections by Candida albicans; see [1]. There are a variety of remedies available to treat these symptoms, Dr. Crook suggests, ranging from dietary modification to colonic irrigation. Mainstream western medicine has ignored these methods and they have not been tested using scientific analysis, and therefore are not considered valid by most in the mainstream western medical establishment; see also [2], [3] for criticisms of these treatments. However, nutritionists have also proposed that these symptoms may be due to intestinal wall damage, known as leaky gut syndrome, due to Candida overgrowth or other effects.

External links

• DermAtlas candidiasis images
• InteliHealth page on candidiasis Presented by InteliHealth reviewed by Harvard Medical School
• National Institute of Allergies and Infections fact sheet on vaginitis/vaginal infections
• The yeast infection homepage
• Links to pictures of Yeast Infection (Hardin MD/Univ of Iowa)