Thrush: causes, symptoms and therapies

It mostly affects children or people with reduced immune defenses and causes whitish plaques in the mouth that can also extend to the esophagus or other body districts.

Thrush is the best-known manifestation of a disorder known as oral candidiasis. It is a mycosis, or an infection caused by a fungus. The microorganism in question is Candida albicans which is an integral part of the bacterial flora present in the oral mucosa of many people.

Who strikes?

Very common in infants and young children, it can also affect adults. In particular, the elderly with dentures or those who, for various reasons, have a compromised immune system.

Candida: identikit of a fungus

Candida albicans is a fungus belonging to the family of saccharomycetes. Normally present in the body, it is able to replicate and give rise to colonies that are located at the level of the vaginal mucosa, that of the oral cavity and the terminal portion of the intestine. Here it occupies a well-defined niche together with other bacteria such as lactobacilli which, all together, represent the bacterial microflora, fundamental to help our body perform some crucial functions such as digestion or protection against external pathogens.

Albicans, however, is only one of many species of Candida present in the human body. Among the best known are, for example, the glabrata (responsible for some urinary infections) and the krusei, two species characterized by high resistance to the main tools of care of albicans. But there is also a “new” one, Candida auris: an isolated species in recent times (2009), which has catalyzed the interest of medicine, among other things, because of its resistance to numerous antifungal drugs.

Symptoms: What does thrush look like in adults?

Thrush, or acute pseudomembranous candidiasis, is the most typical manifestation of Candida infection.

Describing the symptoms, the patient generally alludes to a “white patina” on the tongue. And, in fact, the main feature of this infection is the appearance of white, milky, point-like, lentil-shaped plaques that appear predominantly on the back of the tongue and less often at the level of the palate, gums, tonsils or towards the back of the throat. These injuries, if rubbed, can rupture, losing blood.

In adults, other symptoms include:

• lesions or redness localized in the corners of the mouth,
• difficulty perceiving flavors,
• unpleasant taste sensation in the mouth,
• pain and swelling of the tongue and gums (in some cases, the appearance of stomatitis may occur),
• burning sensation,
• difficulties during meals, both with regard to the ingestion of solid and liquid foods.

The risk of developing infections by this fungus increases in the case of immunocompromised individuals. For example, in people suffering from certain types of cancers or conditions such as HIV, the lesions can spread and expand until they reach the esophagus. This causes difficulty swallowing (dysphagia) and pain (odynophagia): you have the feeling of having something stuck in your throat and consequently you have difficulty feeding. Among the possible consequences also ulcers, irritation and swelling of the esophagus (esophagitis).

In some cases, the fungus can also reach very distant districts, for example coming to affect the joints or toenails (causing the type of phenomenon known as “athlete’s foot“). The genitals also represent an area that can easily be affected by these disorders. In adults, oral infection is not contagious.

And in children?

In addition to the typical whitish plaques, when thrush affects infants or young children, other symptoms are:

• irritability
• loss of appetite and difficulty during the meal, in rare cases with the appearance of vomiting.

The baby can transmit the infection to the mother through breastfeeding. The infection can be repeated over time, passing from the newborn to the mother, always during the feeding of the baby.

The symptoms that can affect the woman are:

• redness, pain, itching at the level of the nipples, even far from the moment of breastfeeding,
• breast pain.

What are the causes?

We now come to the heart of the problem: why does a microorganism normally present in our body suddenly turn into a threat? The cause lies in the immune system. This, under normal conditions, “keeps at bay” the different bacteria and fungi that colonize some mucous membranes of our body, preventing them from proliferating in an uncontrolled way and therefore giving rise to infections.

The use of certain drugs, a period of intense stress, an unhealthy lifestyle or a weakening of the immune system, however, can cause an alteration of the micro-environment and an excessive multiplication of these fungi, until they turn into a real infection.

In the case of newborns, thrush is due to the presence of an immune system that is not yet fully mature. Premature babies are particularly at risk, but any infant can become infected, even more than once.

Another cause is the use of a broad-spectrum antibiotic therapy: this determines a reduction of the oral bacterial flora, allowing the fungi present, in particular those belonging to the genus Candida, to take over.

Identifying the risk of thrush

The main risk factors for the development of Candida albicans infections are:

• reduced immune defences, both in children and adults, following organ transplantation or diseases that cause impairment of the immune system, such as HIV;
• diabetes, due to the excessive amount of sugars present in saliva, which can promote the proliferation of fungi;
• genital infections;
• treatments with drugs such as antibiotics, prednisone or inhaled corticosteroids, which alter the normal balance of bacterial flora in the body;
• presence of dental prostheses.

Diagnosis: detecting thrush is not difficult

Diagnosing this disorder is quite simple, as can be seen from the description of its symptoms.

In the event that the lesions are limited to the mouth, the attending physician or dentist may proceed with the physical examination, by:

• observation of the oral cavity to assess the consistency of the plaques;
• the taking of a small sample from the lesions, to proceed with a laboratory test: this involves the culture of the collected material in order to identify the microorganism responsible for the infection in progress;
• the assessment of the overall state of health, which may also include the execution of other diagnostic tests, to exclude the presence of other diseases.

In the event that the lesions have spread beyond the mucous membrane of the oral cavity, for example up to the esophagus, a specialist visit may be necessary with further examinations, such as:

• biopsy, with tissue and culture to identify the cause of infection;
• endoscopy, to examine the esophagus, stomach and the first part of the intestine, or the duodenum.

How is thrush treated?

The first goal of Candida infection therapy is to stop the spread of the fungus.

The therapeutic approach depends on:

• age
• general state of health,
• cause of infection.

Eliminating other concomitant causes can prevent thrush from occurring again.

In the case of healthy adults and children suffering from mild forms, doctors resort to special mouthwashes or rinses with alkaline solutions. It is also possible to use antifungal drugs: these are topical therapies that act directly on the lesions. The most used active ingredients to eradicate the fungus are fluconazole, miconazole and itraconazole. When, however, the infection spreads to the esophagus (ie an esophagitis is in progress), to the last two solutions it is advisable to prefer fluconazole, to be taken orally, for a period of about 14-21 days.

If these do not work, you can think of using systemic therapies, that is, that act on the whole organism.

If thrush affects a breastfed baby, topical therapy should also be extended to the mother’s nipple and areola. This is to prevent the two from continuing to pass and revise the infection during breastfeeding. Equally important is sterilizing teats and pacifiers before use.

In these circumstances, the use of antifungals is not normally indicated (unless the infection lasts beyond two weeks), but the administration of an antibiotic drug, such as niastatin, is preferred.

Even in the case of adults with impaired immune system, treatment involves the use of drugs that act against the fungus, but in these situations the doctor will also try to act on the cause that caused the reduction of the immune defenses, to prevent the infection from recurring recurrently.

When faced with Candida infections that are localized in other parts of the body, therapeutic strategies can be different, and must be chosen together with your doctor who must make his assessments based on the severity and location of the infection. For example, vaginal Candida can be treated by lavender or vaginal shower, to be performed carefully and only after medical advice.

Below is a table that summarizes the diagnostic-therapeutic approach against thrush according to age.

Age range	Symptoms	Remedies
Children	White plaques inside the oral cavity Irritability Loss of appetite and difficulty during the meal	Special mouthwashes or rinses with alkaline solutions Topical antifungal drugs
Adults	White plaques inside the oral cavity Lesions or redness located in the corners of the mouth Difficulty perceiving flavors Unpleasant taste sensation in the mouth Pain and swelling of the tongue and gums (in some cases the appearance of stomatitis may occur) Burning sensation Difficulties during meals, both with regard to the ingestion of solid and liquid foods.	Antifungal drugs by mouth

Prevention is possible: what to do and what to avoid

There are many actions that can be taken for the prevention of thrush. The aim is to protect the balance of bacterial flora in the area that may be affected.

Take care of your oral hygiene:

• brush your teeth twice a day;
• take care of the hygiene of dental prostheses, if you wear them;
• carry out regular check-ups at the dentist;
• For babies who have not yet put teeth, use a soft toothbrush to gently rub their tongue and gums;
• regularly sterilize pacifiers and bottles;
• rinse your mouth after taking medications, such as corticosteroids for asthma;
• Have regular check-ups if you have diabetes.

It is also very important to always wash your hands thoroughly after changing a newborn’s diaper.

Instead, avoid the following:

• smoking,
• wear dentures throughout the night,
• Continue to wear a prosthesis, if it does not fit perfectly.

As in many cases, prevention also passes through nutrition. Following a healthy diet can help prevent many ailments, including thrush. Ingesting excessive amounts of sugars, in fact, can promote the proliferation of the fungus and should therefore be avoided.