It has been proposed that the asymptomatic colonization with Candida might be associated with a variety of symptoms and cause a “Candida Hypersensitivity Syndrome” [599] This concept was popularized by William Crook, MD in his book The Yeast Connection [491]. Previously, C.O. Truss, a physician from Birmingham, Alabama had proposed the existence of such a malady [2257, 2259]. Other names that have been given to this presumed condition include:

The syndrome is theoretically due to an overgrowth of Candida albicans in the gastrointestinal tract or in association with mucous membranes. The syndrome is said to occur in connection with some or all of the following risk factors:

  1. Use of broad spectrum antibiotics
  2. Use of oral contraceptives
  3. Ingestion of diets rich in yeast-containing foods or readily utilizable carbohydrates.
  4. Pregnancy

Tremendous attention by public media and health magazines has created a large body of uncritical publications on this topic [399, 486, 490, 2046, 2256, 2257, 2258, 2259, 2459]. There are no rigorous data to support these concepts. The whole idea is based on historical controls and no working definition has been ever assessed [220]. Although brief communications by the proponents have appeared in major journals [483, 484, 485, 487, 488, 489, 492], the actual studies performed by these physicians do not appear to have been subjected to peer review. The American Academy of Allergy and Immunology published a position paper in 1986 stating that the concept was “speculative and unproven” [84]. Later, a carefully designed study on the topic by Dismukes et al. demonstrated that the condition does not appear to be reproducible or verifiable [599].

Clinical Manifestations

There is a broad range of symptoms that have been associated with this syndrome. They can be classified in the following groups, although it is not clear how many or which of them are required to make a diagnosis nor is there scientific data linking these multiple clinical manifestations with Candida albicans overgrowth [220, 262]:

  • Vaginal. Recurrent episodes of Candida vaginitis associated with the classic symptoms of pruritus, burning and abnormal discharge.
  • Gastrointestinal. Heartburn, bloating, diarrhea or constipation.
  • Respiratory allergy. Rhinitis, sneezing and/or wheezing.
  • Central nervous system. Anxiety, depression, memory deficits and/or loss of ability to concentrate.
  • Menstrual abnormalities. Severe premenstrual tension and/or menstrual irregularities.
  • Other Systemic Symptoms. Fatigue, headache and/or irritability.

Specific Diagnostic Strategies

The proponents of the existence of this syndrome base their diagnosis on the clinical picture previously discussed [490, 491, 2459]. There is no laboratory test that allows a clear identification of patients affected with this presumed disorder. Actually, “no clear definition of the disease has ever been advanced” [220]. Considering these facts, it is impossible to set criteria to establish and identify patients affected with this supposed disease.

From a practical viewpoint, we recommend that all women with (A):recurrent vaginitis be carefully evaluated for possible causative factors. Patients with more general complaints should receive a general physical examination. A CBC, general serum chemistries (including liver enzymes), and thyroid studies should be checked to eliminate the possibility of an anemia, subclinical hepatitis, and so forth. Finally, Renfro et al. reported that approximately two-thirds of patients with chronic fatigue had an underlying psychiatric diagnosis [1893].


Proponents of this syndrome have recommended such therapies as:

  • Long-term therapy with antifungal agents at increasing doses until resolution of symptoms. Oral and usually vaginal nystatin are recommended. Other azoles, such as ketoconazole have been also used [262].
  • Diet modification including restriction of sugar and other simple carbohydrates [487].
  • Candida allergy shots [220].
  • Avoidance of mouldy environments [220].

The value of these therapies is unknown. Dismukes et al. conducted a prospective double-blind study to assess the impact of antifungal therapy on this condition [599]. This study compared oral and vaginal nystatin with placebo in 42 premenopausal women with the presumed diagnosis of chronic candidiasis. The remarkable finding of this study was that nystatin did not “reduce systemic or psychological symptoms more than placebo did “[599]. One of the major proponents of the syndrome, Doctor William Crook criticized the study by saying that nystatin is no more than one of the components of the “comprehensive and multimodal therapy” required for this condition [487]. The same author agreed on the urgent need for more scientific studies on the topic. However, a recently done and detailed Medline search on the topic yielded only the data that we have discussed.

Chronic Candidiasis FAQ

We often receive inquiries about the diagnosis and treatment of chronic candidiasis. Here is our FAQ list:

  1. How can I decide if I have chronic candidiasis? Answer: We don’t know. The syndrome has never been clearly defined and a workable diagnostic approach has never been put forth. While we have no doubt that there are individuals who suffer from some (or all) of the (A):symptoms listed above, we are not aware of any testing procedure that can link these symptoms to a candidal infection.
  2. My doctor cultured Candida from my stool. What does this mean? Answer: Candida spp. are frequent asymptomatic colonizers of the skin and bowel. Such cultures are of little significance unless you are critically ill in an ICU or are receiving cancer chemotherapy.
  3. I took _______ (name of drug) or I altered my diet to include (or exclude) _______ (name of food) and now I feel better. Doesn’t that mean I have (had) chronic candidiasis? Answer: The most common form of this question is “I took fluconazole and now I feel better–does this mean I had chronic candidiasis?” While we’re glad you feel better, response to fluconazole is not a diagnostic tool. The various antifungal drugs have effects that go beyond the fungi (for example, fluconazole interacts with the enzyme systems of people, not just of fungi) and many diseases have a natural course of progression and regression. Similar concepts apply to changes in diet. If something makes you feel better, we’re delighted for you. We just don’t know what it means.
  4. I still really think I might have chronic candidiasis. What should I do? Answer: At the risk of being repetitive, we’ll say it again: We don’t know of any useful approaches to diagnosing or treating chronic candidiasis. You should see a competent physician and be checked for the things that we do know how to diagnose (see discussion above). If these tests are negative, then we have nothing too specific to offer other than sympathy. We are not denying your symptoms. Rather, we honestly don’t know what to do about them. If you can identify something that makes you feel better, then we’ll cheer for you!
  5. Is “yeast” the same as Candida? Answer: The term “yeast” is relatively imprecise. Medical mycologists use this term to describe fungi that reproduce predominantly by budding or fission. There are many genera of fungi that fit in this category. Beer and bread makers use the term to refer to Saccharomyces cerevisiae. Doctors sometimes use the term “yeast infection” to refer to Candida spp. and its diseases. For example, yeast vaginitis is the colloquial phrase for candidal vaginitis.