OVERVIEW

What is pulmonary candidiasis?

Pulmonary candidiasis is an acute, subacute, or chronic bronchial or pulmonary infection caused by Candida albicans or other Candida species. Due to the strong tissue adhesion and higher pathogenicity of Candida albicans compared to other Candida species, infections caused by Candida albicans are clinically the most severe and common.

Is pulmonary candidiasis common?

It is common but generally occurs in patients with long-term antibiotic use leading to dysbiosis or those with compromised immune systems. Immunocompromised conditions include cancer patients undergoing radiotherapy or chemotherapy, organ transplant recipients on long-term immunosuppressants, HIV/AIDS patients, and individuals with diabetes.

Is pulmonary candidiasis the same as typical pneumonia?

What the general public typically refers to as pneumonia is bacterial pneumonia. However, many pathogens can infect the lungs, causing inflammation and nonspecific symptoms such as cough, sputum production, and fever. Common pathogens include bacteria, viruses, fungi, Mycoplasma, and Chlamydia. Pulmonary candidiasis is a type of fungal lung infection.

Is pulmonary candidiasis contagious?

Pulmonary candidiasis is not a contagious disease. Healthy individuals caring for such patients will not be infected.

SYMPTOMS

What are the manifestations of pulmonary candidiasis?

• Candida bronchitis: Caused by Candida infection of the bronchi. Typical symptoms include paroxysmal irritating cough, initially with copious white frothy sputum, which later becomes thick and paste-like. Occasional blood-streaked sputum may occur, accompanied by breathlessness and shortness of breath, particularly noticeable at night. Fever is usually absent. Physical examination may occasionally reveal dry rales in both lungs. Chest X-rays may only show thickened lung markings in the middle and lower lung fields.

• Candida pneumonia: Caused by Candida infection of the lung lobes. Typical symptoms include severe coughing with thick, white, jelly-like sputum, occasional hemoptysis, and often low-grade fever. Severe cases may present with dyspnea. Physical examination may reveal dry and wet rales in both lungs. Chest X-rays may show increased lung markings in the lower lobes, scattered nodules of varying shapes and sizes, or large infiltrates typical of pneumonia, possibly with cavitation.

• Allergic reactions: If allergic to Candida, symptoms may also include rhinorrhea, sneezing, and asthma in addition to the above. Physical examination may reveal typical wheezing in the lungs.

Can pulmonary candidiasis lead to other complications?

Generally, no other complications occur. However, in patients with extremely low immunity, hematogenous dissemination may occur, where the pathogen spreads through the bloodstream to other sites, causing infections. Severe cases may involve the brain, leading to meningitis, encephalitis, or brain abscesses.

What conditions should pulmonary candidiasis be differentiated from?

Pulmonary candidiasis should be differentiated from bacterial pneumonia, tuberculosis, viral pneumonia, parasitic pneumonia, and other fungal pneumonias.

CAUSES

What causes pulmonary candidiasis?

The pathogen of pulmonary candidiasis is Candida, also known as pseudohyphae yeast, which is an opportunistic pathogenic fungus (meaning it generally does not cause disease but becomes pathogenic under specific conditions). Among these, Candida albicans, or white Candida, is the most common.

This type of fungus can parasitize normal human body parts such as the oral cavity, upper respiratory tract, intestines, and vagina. It has weak pathogenicity and usually does not cause disease in humans. However, when long-term use of antibiotics disrupts the balance of normal flora or when immunity is weakened, Candida can invade the skin, mucous membranes, or internal organs, leading to disease.

Pulmonary candidiasis is mostly caused by oral Candida spreading along the bronchi, but it can also result from Candida in other parts of the body spreading to the lungs through the bloodstream, causing infection.

DIAGNOSIS

How is pulmonary candidiasis diagnosed?

Doctors generally diagnose it based on the patient's underlying conditions, predisposing factors, typical clinical manifestations, and pathogenic tests, after ruling out other diseases.

What tests are needed for patients with pulmonary candidiasis? Why are these tests performed? What precautions should be taken?

• Sputum examination: Convenient, simple, and non-invasive. However, since Candida may colonize the oral cavity of healthy individuals, a single detection of Candida in sputum cannot diagnose pulmonary candidiasis. At least three consecutive sputum smears showing hyphae or positive cultures are required for reference. Precautions: To avoid oral Candida contamination, rinse the mouth several times with 3% hydrogen peroxide before collecting sputum, discard the first two samples, and send subsequent sputum for testing immediately to ensure freshness.

• Direct sampling of lower respiratory secretions or lung tissue: To avoid oral or upper respiratory tract contamination, fiberoptic bronchoscopy or tracheal intubation can be used to directly collect lower respiratory secretions or lung tissue for smear or culture. A positive result confirms the diagnosis. However, these invasive procedures may require local or general anesthesia depending on patient tolerance and carry certain risks.

• Imaging tests: Chest X-rays or CT scans can be performed. Since other pulmonary infections may show similar findings, imaging alone cannot confirm the diagnosis but aids in auxiliary assessment.

• Immunological tests: Currently, their sensitivity and specificity are insufficient, so they are not routinely used.

TREATMENT

Which department should I visit for pulmonary candidiasis?

Respiratory Medicine.

Does pulmonary candidiasis require hospitalization?

Due to the special susceptibility of the affected population, hospitalization is usually required.

How is pulmonary candidiasis treated?

• For mild cases, the condition often gradually improves after eliminating predisposing factors (such as discontinuing broad-spectrum antibiotics, immunosuppressants, or stopping chemotherapy/radiotherapy that causes microbial imbalance and reduced immunity), along with supportive care to enhance resistance.

• Severe cases require prompt antifungal medication (e.g., fluconazole, amphotericin B). Treatment duration depends on symptom monitoring, clinical signs, and patient tolerance. Common gastrointestinal side effects of antifungals include nausea, vomiting, diarrhea, and potential liver damage, necessitating strict liver function monitoring during treatment.

DIET & LIFESTYLE

What should patients with pulmonary candidiasis pay attention to in their diet?

Eat more fresh vegetables and fruits to supplement vitamins, and consume high-quality protein such as egg whites, milk, and fish.

What should patients with pulmonary candidiasis pay attention to in daily life?

Maintain a regular routine, avoid excessive fatigue and insufficient sleep, quit smoking and alcohol, manage emotions, avoid anger and agitation, stay in a positive mood, reduce stress, engage in appropriate physical exercise, and enhance immunity.

Does pulmonary candidiasis require follow-up examinations?

Generally not. After completing treatment, monitor for any recurrence of symptoms or signs. If taking antifungal medications, outpatient follow-ups are needed to monitor liver function.

PREVENTION

Can pulmonary candidiasis be prevented?

Yes. Boosting immunity through balanced nutrition, moderate exercise, and minimizing risk factors (such as strictly controlling antibiotic dosage and duration, using 3% sodium bicarbonate mouthwash to suppress oral fungal growth during prolonged antibiotic use, avoiding misuse of immunosuppressants like glucocorticoids, and managing blood sugar in diabetic patients) can help prevent it.

When necessary, immune-enhancing medications like immunoglobulins or thymosin may reduce the likelihood of infection.