Discover How a Complex Mix of Different Factors Cause Yeast Infection

Infections from Candida can be local, involving one section of the body, such as the mouth, or it can be systemic, involving more than one area of the body.

Causes

Candida is normally kept under control by the population of other natural organisms in the body and the body's defense system (T-cells, neutrophils). When there is a change in the organism population (e.g. antibiotic use) or the body's defense system is not working properly (cancer, HIV), Candida may become problematic, causing harm to the body, and resulting in a yeast infection.

In addition to causes mentioned above, yeast infections of the skin may be due to constant exposure to friction, heat and moisture. Here are some common causes of yeast infection:

Medication use: Antibiotic or birth control pill use, for example, can alter the normal flora of the body and create an ideal environment for Candida to multiply and flourish

Denture use: Individuals who use full dentures that are not removed at night can develop an oral yeast infection. Chronic redness and swelling of the areas of the mouth that contacts the fitting surface of the denture are characteristic

On skin surfaces that are exposed to heat and moisture: Diaper candidasis can result from prolonged exposed of the skin to wet diapers. A yeast infection can also develop under the skin (intertrigo) especially underneath the breasts, or sunder skin flaps in obese individuals. Yeast prefer warm, moist and dark places to grow.

Immunocompromised state: People with cancer, HIV, intensive care unit (ICU) hospitalization, organ dysfunction, immune disorders, and diabetes mellitus are more susceptible to yeast infections.

Immunosuppressive therapy: People who actively take medications such as steroids are under chemotherapy treatment can develop decreased function in their immune system and become more susceptible to yeast infections

Breaks in tissue or skin: Any break in the skin, the body's first line of defense against infections, will increase the chances of developing a yeast infection. This includes recent trauma, IV lines, catheter use, tissue damage from chemotherapy, and burn victims

Recurring Yeast Infection

Recurring yeast infections of the skin, mouth, nails, and vagina can occur in individuals who have a decreased immunity (the ability to prevent infections) due to a low T-cell response or a low neutrophil count.

• HIV: People with the Humuan Immunodificeny virus (HIV) have a low-T cell response.
  
• Leukemia: People with leukemia have low neutrophils, making them at risk for recurrent yeast infections.
  
• Immune disorders: People with conditions that decrease the body's immunity include T-cell immunity and diabetes mellitus have recurrent yeast infections
  
• Endocrine disorders: Disorders such as hypoparathyroidism, hypothyroidism, and hypoadrenalism are prone to recurring yeast infections
  

The body normally has specialized cells that make up the immunity system. Depending on the type of immunodeficiency a person has, infection from Candida can manifest different ways.

Lymphocytes and cell-mediated immunity are important in the prevention of Mucosal Candidiasis. Therefore, patients with T-cell deficiency, such as Human Immunodeficiency Virus (HIV), have a high risk of developing recurrent and/or persistent mucocutaneous candidiasis.

Patients with Neutropenia are at risk for invasive candidiasis and Candidemia as functioning monocytes and polymorphonuclear cells are responsible for killing pseudohyphae and blastospores. Complement and immunoglobulins are necessary for intracellular killing of the organisms and patients with deficiencies can have a more prolonged and complicated course of candidal infection.

Diagnosing Candida Infection

Candida infection is usually diagnosed based on signs and symptoms. Skin, mouth, vaginal yeast infections are easier to diagnose because of their distinct appearance and symptoms of an itchy, red rash with a distinct border and satellite lesions for skin infections; and white flecks in the surfaces inside the mouth for an oral thrush.

Patients with systemic disease that spread throughout the body may show signs and symptoms similar to bacterial infections with fever and pain, so it is important to determine if yeast are the cause.

For Mucocutaneous Candidasis, the most common way to diagnose Candida is to scrape the lesion, revealing a red or bleeding base. A potassium hydroxide test or a methylene blue gram stain, revealing budding yeast or hyphae confirms the diagnosis of a Candida infection. Cultures of the nail bed may distinguish onychomycosis (candida infection of the nails) versus noninfectious causes.

For cases of Systemic Candida Infections, blood tests can be performed, but they are not relied upon for initiation of treatment since the results can take days, creating a treatment delay for doctors. Cultures are not routinely performed because of the same reason. Blood cultures are positive in only 50-60% of cases of disseminated disease.

Urinalysis may be helpful, and results may be indicative of either colonization or renal candidiasis. Physicians can sometimes obtain cultures of sterile sites. Positive results from blood cultures from these sights indicate the presence of invasive candida and infection.

The serum 1-3 D-glucan detection assay has been used and it predicts the presence of candia by measuring levels of beta-glucan (a fungal cell wall component).