A yeast infection can affect the kidneys

Thrush and other candida infections

What is a Candida Infection?

Candidiasis is an excessive proliferation of yeasts of the genus Candida in or on the human body. Because the human body is not sterile - a multitude of different bacteria, protozoa and fungi settle on the skin and in the intestines, among other things. This naturally existing bacterial colonization is also referred to as resident skin or mucous membrane flora or so-called local flora. The local flora is important and useful for the body and consists of mostly harmless germs (commensals), which protect against infestation with pathogenic microorganisms.

The Candida genus includes numerous yeasts, which, even in healthy people, often settle on the skin, mucous membranes of the mouth and throat and the external genital organs and in more than half of Europeans also in the colon. The most commonly detected species of Candida is Candida albicans. During birth or infancy, the fungus gets on and into the body, where it multiplies as a component of the skin and intestinal flora. However, other microorganisms and the immune system limit the growth of Candida albicansso that it usually does not cause discomfort ("colonization").

However, if Candida yeasts multiply excessively and manage to break through the skin or the mucous membrane of the body, they trigger various symptoms and clinical pictures (see section Symptoms). Examples are inflammation of the skin in the genital area (Vaginal mycosis or Balanitis) and diaper area (diaper rash), as well as in and on the mouth (Oral thrush, "lazy licks"). The body folds ("intertrigines") are particularly affected, especially if moisture can accumulate there (Candidosis intertriginosa, intertriginous candida). For example, between the fingers and toes or in the large folds of the body, such as the groin. Candida yeasts can also spread throughout the body via the blood vessels and cause life-threatening blood poisoning (sepsis). Affected by such systemic candida infections are above all people with a severely impaired immune system.

Causes and Risk Factors

Candidiasis is caused by the proliferation of yeast fungi of the genus Candida in or on the body. As described above, Candida species colonize skin and mucous membranes even in healthy people. The yeast found most frequently is Candida albicans (C. albicans). Other important causative agents of candidiasis are

  • C. glabrata
  • C. guilliermondii
  • C. tropicalis
  • C. krusei
  • C. parapsilosis

A colonization of the skin or mucous membranes with Candida is not a disease per se. Symptoms and clinical pictures only arise when certain beneficial external factors, such as a weakened immune system and impaired barrier function of the skin and mucous membrane, are added. Furthermore, Candida yeasts use a variety of mechanisms with which they can disrupt and undermine the defense against infection. These are particularly pronounced in Candida albicans, the most common pathogen causing Candida infections.

General Risk Factors for Candida Infection

These include changes in the skin or mucous membranes that make it easier for the fungus to penetrate the body. For example

  • chronic wounds
  • chronic moisture penetration of the skin (for example in body folds)
  • increased tendency to perspire with insufficient evaporation
  • if the skin is blocked from the air supply by bandages (occlusion)

A weakened immune defense favors the spread of the fungus, for example in the case of congenital or acquired immunodeficiency, such as occurs during chemotherapy or in tumor diseases. An immune deficiency can also occur as a result of

  • Infections
  • severe burns
  • Metabolic disorders such as diabetes mellitus
  • stress

Elderly people and very small infants or premature babies also often only have a reduced immune system. Some drugs, such as corticosteroids, suppress or impair the function of the immune system, making candida infections more likely. Treatment with antibiotics can change the normal skin and intestinal flora and thus enable the fungus to grow more rapidly.

Particular risk factors for oral thrush

Badly fitting dentures can cause candidiasis in the mouth (oral thrush) through irritation of the mucous membranes. The same applies to a dry mouth due to insufficient saliva production. Otherwise, oral thrush mainly affects infants and adults with a weakened immune system (for example, during chemotherapy, in the case of tumor diseases or AIDS). Smoking also promotes the development of oral thrush.

Specific Risk Factors for Candida Skin Infections

Candidiasis of the skin often also affect people who belong to certain professional groups. Since the fungus multiplies particularly well on damp skin, cleaning staff, for example, are particularly often affected by candidiasis, as are confectioners, butchers and workers at refrigerated counters ("glove wearers"). Candida yeasts can be involved in the development of diaper rash in infants. Because under a damp and warm diaper, mushrooms are offered an ideal growth climate. Another risk factor for candida skin infections is obesity. In fat people, moisture can collect in skin folds, which promotes a fungal infection (intertriginous candidiasis).


Candidiasis of the skin

The yeasts like to infect areas where skin folds lie on top of each other (intertriginous Candida). Here the skin is moist and warm and offers Candida yeasts optimal growth conditions. Typical parts of the body for intertriginous candidiasis are therefore located

  • under the breasts
  • in the armpits
  • in the anal area
  • between skin folds in the groin region and the lower abdomen
  • in the spaces between fingers or toes

In addition to the skin, the nails and nail wall can also be affected by a candida infection. Here are the inflamed areas

  • reddened
  • swollen
  • pain when touched

Scaling of the affected skin is typical. Often there is a red border ("so-called ruff scaling"), sometimes with pustules. The affected areas can itch or burn, and even pain.

Diaper rash

Candida infections often occur in infants and young children as well. In the case of diaper rash, for example, the inflamed skin in the diaper area can be colonized with Candida (diaper thrush).

Genital Candida Infestation

The Candida yeast can also infect the external genital organs. Candida infections are not usually transmitted through sexual intercourse, but in a broader sense they belong to the sexually transmitted diseases. In women, they are favored, among other things, by high levels of estrogen (for example during pregnancy).

It occurs with candidiasis of the vagina (vaginal mycosis)

  • itch
  • Burn
  • and redness.

The mucous membrane is swollen and partially covered with a whitish coating. You may experience a crumbly white discharge.

Men can become infected with candida on the glans (balanitis, balanoposthitis). The glans and / or foreskin are inflamed; they itch and burn, and blisters and pustules can form.

Oral thrush

Thrush is the name given to candidiasis of the mouth and throat. It mostly affects people with weakened immune systems. Using asthma sprays that contain cortisone can make the infection more likely.

The affected areas are reddened and covered with a whitish coating, whereby the wound base bleeds slightly when trying to wipe it off. If it extends into the pharynx, there is also difficulty swallowing. Candidiasis can also affect the esophagus and spread to the gastrointestinal tract.

Systemic infection

Systemic infections with Candida mainly affect people with weakened immune systems. They are often found in intensive care units or in people who suffer from cancer, AIDS or other diseases that impair the immune system. Blood poisoning with Candida (sepsis) or a pronounced infestation of the internal organs can be life-threatening. The Candida yeasts can attack and damage all organs. The lungs are particularly often affected (candida pneumonia), too

  • Kidneys
  • liver
  • spleen
  • the eye (endophthalmitis)
  • the inner wall of the heart (endocarditis)
  • brain
  • annoy

The symptoms depend on the organs affected.


The suspicion of a Candida infection quickly arises based on the typical symptoms. To detect the yeast, the doctor can, for example, take a swab from the affected skin or mucous membrane with a cotton swab. Alternatively, a piece of affected skin, nail or mucous membrane is also suitable for examination. A direct examination of the material with the aid of a microscope can provide an initial indication of the presence of a fungal infection within a few minutes. The fungal culture using certain nutrient media or molecular methods then allow the unequivocal identification of the pathogen. This is particularly important if there have been several relapses of a yeast disease despite the use of medication, as some Candida species can be resistant to the antifungal agent used. However, the mere detection of a yeast in the laboratory does not allow the diagnosis of a fungal disease, but the corresponding symptoms must also be present. Since an immune deficiency is often behind a Candida infection, it is important to clarify which risk factors for a Candida infection are present in the person concerned. If these do not adequately explain the infection, further targeted searches should be made for possible causes of a weak immune system. A Candida infection can be the first indication of diabetes mellitus ("diabetes") or an immunodeficiency disease. If systemic candidiasis is suspected, other body fluids should be examined depending on the symptoms:

  • blood
  • Nerve fluid (liquor)
  • urine


Candida infections of the skin can in most cases be successfully treated with anti-fungal or growth-inhibiting agents, so-called topical antimycotics. The most suitable base is selected according to the localization: creams and ointments especially for the skin on the trunk, arms and legs, pastes especially for body folds, varnishes for the nails, suppositories and tablets for use in the vagina, lozenges and Suspensions for thrush of the oral mucosa.

Frequently used active ingredients for the treatment of candidiasis are for example nystatin, clotrimazole, miconazole, ciclopiroxolamine, fluconazole, itraconazole and amphotericin B.

In the case of systemic candidiasis or if external treatment is not sufficient, the antimycotics can also be prescribed as tablets or juice or administered by infusion via the vein.

Important for all forms of therapy: In order to reliably kill the fungi, the agents must be used regularly for a certain period of time. If treatment is stopped prematurely, there is a risk that the fungus will return. So be sure to follow your doctor's advice carefully and use the antifungal drugs for as long as he has prescribed them! In the case of Candida infections of the skin, it can make sense to boil the laundry or use an appropriate hygiene rinse.

Oral thrush

In the case of thrush in the mouth, treatment is usually given topically with mouthwashes, lozenges, or gels and suspensions for application. It can be helpful to change your toothbrush and other oral care items to prevent the infection from spreading. Dentures should be cleaned two to three times a week in a bath with chlorhexidine solution or commercially available denture cleaning tablets and professionally cleaned by the dentist at regular intervals. Boil pacifiers and teats for infants.

intertriginous candidiasis

In the case of intertriginous candidiasis, it is also important that there is no longer a damp chamber. For this, the affected skin regions must be adequately ventilated. Gauze strips inserted into the folds (for example in the groin, folds under the chest, armpits) help to keep the affected areas dry. Anyone who cares for relatives with intertrigo in need of care should seek detailed advice from a doctor or nursing staff.

Pathogen does not mean disease

Candida albicans has temporarily become a "fashion diagnosis". Again and again one hears claims that the yeast in the intestines causes numerous diseases, such as depression or migraines. It is said that a diet rich in sugar would "feed" the Candida fungus in the intestines. Therefore, according to some advisors, an anti-fungal diet and / or colonic irrigation should help.

However, these claims have no scientific basis. Candida occurs in about every second healthy Central European in the large intestine and does not cause any symptoms there. People without immune deficiency rarely suffer from infections with the fungus. Detection of Candida species on the skin or in the intestines does not always indicate an infection. Candidiasis should only be considered and appropriate treatment started if the symptoms are present (see above).