Superficial persistent and recurrent infections caused by Candida species (most commonly Candida albicans) are the hallmark of chronic mucocutaneous candidiasis (CMC) . The frequently affected areas of the body are the buccal mucosa, palate, tongue, and the oropharynx.
Most infections occur in early childhood . However, adults may also be affected by CMC. Infants usually present with a diaper rash or a thrush refractory to the treatment, often progressing to more extensive disease.
Physical examination may yield definitive diagnostic clues to CMC. Oral lesions include white plaques that are adherent to the mucosa (thrush). Oropharyngeal plaques may extend to the esophagus. Angular cheilitis is present in some individuals.
Cracked and hyperkeratotic nails with prominent discoloration are commonly seen. The periungual regions are edematous and erythematous. Lesions of the skin are mostly seen on the extremities, with thickened, red plaques being a characteristic finding seen in many affected patients. Scalp lesions may be present in CMC and frequently progress to scarring alopecia.
An important differential diagnosis is a candidal infection occurring in immunocompromised states.
A patient presenting with clinical features suggestive of CMC should undergo thorough testing. Samples may be scraped from the infected lesions and microscopically examined in 10-20 % potassium hydroxide (KOH) to reveal the pseudohyphae and yeast cells . Additional stains that may help in identification of the fungi are the Parker blue-black ink and chlorazol black E stain.
Skin biopsies are usually not required to make a diagnosis of CMC. They may, however, be useful in ruling out the presence of a primary dermatosis. Subcorneal pustules along with parakeratosis and hyperkeratosis are visualized on a hematoxylin and eosin stained samples. The silver stain and the periodic acid-Schiff stain may also be beneficial in identifying these lesions.
In individuals suspected of having CMC, it is imperative to perform tests to check for primary or secondary immunodeficiencies and endocrine abnormalities. A routine testing protocol should include a complete blood count, blood glucose level, human immunodeficiency virus (HIV) testing, liver function tests, serum electrolytes, plasma adrenocorticotropic hormone (ACTH), and serum cortisol level. Patients suffering from isolated immunoglobulin G, immunoglobulin A, or immunoglobulin M subclass deficiencies have also been reported .
Genetic testing for the AIRE gene and anti-interferon-1 antibodies are some of the novel additions to the laboratory evaluation of CMC   .