What is fungal infection?

Mold is a relatively broad concept, and the most common type of mold is Candida, which can cause a variety of diseases and invade the oral cavity, esophagus, genitals and other parts, thereby causing fungal infections. It is contagious to a certain extent and can spread or invade the endocardium through the liver and spleen, causing endocarditis, etc., and sometimes it can become an infectious disease.

What is fungal infection?

Candidiasis is a fungal disease caused by Candida species, especially Candida albicans. The pathogen can invade the skin and mucous membranes, and can also affect the internal organs. The syndromes are usually classified by site of involvement; the two most common syndromes are mucocutaneous candidiasis (eg, oropharyngeal candidiasis or thrush, esophagitis, and vaginitis) and invasive or deep-organ candidiasis (eg, candidemia, chronic disseminated or hepatosplenic candidiasis, endocarditis, etc). In most patients, candidiasis is an opportunistic infection.

(1) Oropharyngeal candidiasis: The most common type is Candida albicans oropharyngeal inflammation, also known as acute pseudomembranous candidiasis and thrush. Candida albicans stomatitis is common in the tongue, soft palate, buccal mucosa, gums, pharynx, etc. The patient felt pain, difficulty swallowing, and loss of appetite. It is most common in children and the elderly; it appears in newborns one week after birth; Candida albicans stomatitis is rare in adults. For patients who have been using broad-spectrum antibiotics, corticosteroids, immunosuppressants for a long time, radiotherapy, chemotherapy, or have inducing factors such as leukemia and malignant tumors, if candidal stomatitis occurs, they should be highly vigilant to see whether it is accompanied by respiratory tract, digestive tract or even disseminated candidal infection. Further fungal examination should be carried out promptly. (2) Esophageal candidiasis Candidal esophagitis is mainly seen in patients with malignant tumors and AIDS, and is manifested by esophageal spasm, dysphagia, burning pain behind the sternum, and occasionally massive upper gastrointestinal bleeding. Esophagoscopy revealed pigmented plaques and extensive inflammation on the mucosa.

2. Skin candidiasis

(1) Candidal intertriginous infection often affects areas where smooth skin directly rubs against each other. Such as armpits, under breasts, groin, perianal area, gluteal groove, perineum, etc. There is often excessive sweating, local moisture and poor ventilation. It is more common in obese middle-aged women and children. It initially presents as intertriginous erythema, papules or small blisters, which then expand and merge into clearer erythema. After the blisters burst, they will desquamate or form erosive surfaces with a small amount of exudate, occasional cracks and pain. They are distributed in satellite shapes and often cause pruritus.

3. Disseminated candidiasis

A serious, life-threatening fungal infection. Due to the involvement of multiple organs, the clinical manifestations are varied. (1) Candidemia: Single or multiple blood cultures are positive for Candida, but there is no evidence of organ involvement. It is more common in patients with agranulocytosis or other high-risk patients. The most common clinical manifestation is fever, which can often exceed 38°C. Occasionally there may be chills and low blood pressure. (2) Acute disseminated candidiasis is characterized by persistent fever and is unresponsive to broad-spectrum antibiotics. Depending on the affected area, it may manifest as meningitis, brain abscess, encephalitis, myocarditis, endocarditis, osteomyelitis, arthritis, myositis (muscle tenderness), etc. 30% of non-granulocytopenic patients develop endophthalmitis, which manifests as blurred vision and eye pain. Ophthalmic examination may reveal retinitis, choroiditis, vitreous abscess and even anterior chamber abscess, which may be unilateral or bilateral and may lead to blindness. The skin is affected, with painful red papules with clear edges and necrotic eschars. There may also be deep abscesses, gangrenous deep pustular lesions, cellulitis, nodules, etc. Patients with thrombocytopenia may have purpura.

4. Deep Organ Candidiasis

(1) Urinary tract candidiasis ① Renal candidiasis Most disseminated candidiasis involve the kidneys, and a few are caused by ascending urinary tract infection. The main symptoms are fever, chills, back pain and abdominal pain. It often leads to renal abscess formation or hydronephrosis or anuria due to bacterial obstruction. Infants often have little or no urine. ② Candidal cystitis has similar symptoms to bacterial cystitis, including frequent urination, dysuria, urgency, difficulty urinating, and hematuria. Urine test was positive. (2) Lower respiratory tract candidiasis is mostly endogenous infection of Candida albicans in the bronchi and lungs.