What Is a Fungal Skin Infection?

Fungal infection: There are more than 300 species of fungal pathogenic fungi. With the exception of new types of cryptococcus and mushrooms, medically significant pathogenic fungi are almost always molds. According to the different invading parts of the human body, the pathogenic fungi are clinically divided into shallow fungi and deep fungi. Fungal enteritis is a deep mycosis. Superficial fungi (tinea fungi) only invade the skin, hair, and fingernails, while deep fungi can invade human skin, mucous membranes, deep tissues and internal organs, and even cause systemic disseminated infections. Deep fungal infections in the intestine are manifested as fungal enteritis, which can exist independently such as Candida infantis enteritis, or as a manifestation of systemic fungal infections, such as AIDS with disseminated histoplasmosis.

Basic Information

Causes of fungal infections

Fungal infectious diseases are classified into four categories according to the parts of the fungus that invade the human body: superficial mycosis, dermatomycosis, subcutaneous mycosis, and systemic mycosis; the former two are collectively called superficial mycosis, and the latter two are also called For deep mycosis.

Clinical manifestations of fungal infections

Superficial mycosis

The infection is limited to the outermost layer of the stratum corneum of the skin, and there is little or no tissue reaction. When the hair is infected, it only affects the hair surface and rarely damages the hair. It mainly includes tinea versicolor, tinea versicolor, and sarcoidosis.

2. Dermatomycosis

The infection involves the stratum corneum and skin appendages, such as hair and decks, which can extensively destroy the structure of these tissues and are accompanied by varying degrees of host immune responses; the most common of these fungal infections is dermatophytosis, which is caused by other fungi Infections also include skin candidiasis.

Dermatophytosis can be divided into various types of ringworm such as athlete's foot (commonly known as "athlete's foot"), hand ringworm, body ringworm, jock itch, onychomycosis, and tinea pedis according to different disease sites; it occurs widely in the world and is the most common Common fungal diseases with high incidence.

3. Subcutaneous mycosis

Infected skin and subcutaneous tissues, including muscles and connective tissues, are generally not spread to important organs through blood flow; however, some infections can slowly spread from the lesion to surrounding tissues, such as foot fungi, and others spread along the lymphatic vessels. , Such as sporotrichosis, pigmented blastomycosis. Subcutaneous fungi in immunocompromised patients have the potential to spread throughout the body.

4. Systemic mycosis

In addition to invading the skin and subcutaneous tissues, it also involves tissues and organs, and even causes disseminated infections, also known as invasive fungal infections. In recent years, with the widespread application of high-efficiency, broad-spectrum antibiotics, immunosuppressive agents, and anti-malignant tumor drugs, organ transplantation, catheter technology, and other interventional treatments for surgery have been carried out. Systemic mycosis is increasing, new pathogenic bacteria are constantly appearing, and the disease is getting worse. It mainly includes candidiasis, aspergillosis, cryptococcosis, zygomycosis, and Penicillium maneffei.

Fungal infection test

1. Inquire about the history of trauma and surgery, the time and place of the injury, the treatment after the injury, the time of onset, the development of the disease, and the history of tetanus vaccination. For female patients, the history of childbirth or abortion should be consulted; For newborns, you should ask about your birth history and umbilical cord management. A few cases had no history of injury and no obvious wounds were seen.

2. Check the injured part and the wound, whether there is any spasms and twitches in the muscles around the wound, pay special attention to whether the rectus abdominis is rigid. If there is exudate or shed tissue in the wound, bacteriological examination (including smear and anaerobic culture) and pathological examination should be performed.

Fungal infection diagnosis

Diagnosis is based on medical history, clinical manifestations, and examination.

Differential diagnosis of fungal infections

If fungal enteritis needs to be distinguished from intestinal diarrheal diseases:

Cholera

Pandemics are now rare, mostly local outbreaks. The patient had severe vomiting and diarrhea, and the vomiting and diarrhea exhibited a water-like or yellow water-like appearance. There was no abdominal pain, no fever, and severe dehydration and microcirculation failure often occurred quickly. Examination of vomitus and laxative microscopy revealed a large number of Vibrio in fish-like motion.

2. Bacterial dysentery

Onset is all year round, more common in summer and autumn. The main lesion is purulent inflammation of the colon. The patient had less vomiting, often had fever, diarrhea with abdominal pain, severe back pain, and left lower abdominal tenderness. Stool is mixed with pus and blood, and microscopic examination shows red blood cells, pus cells, and macrophages, and dysentery bacilli grow in culture.

3. Amoebic dysentery

Focus on distribution. Patients often have an onset, with varying degrees of diarrhea, less toxemia, abdominal pain and acute aftermath are not obvious, and quite similar to fungal enteritis. However, feces and pus and blood are not mixed, and the typical ones are jam-like and stinky. Microscopic examination is mainly red blood cells, and amoeba trophozoites and Charco-Raydon crystals can be seen. Sigmoidoscopy revealed that the intestinal mucosa was scattered in the ulcers, the edges were neat, the congestion was raised, and the mucosa between the ulcers was normal. The ulcers can be seen on the ulcer smear or biopsy.

4. Typhoid and Paratyphoid

Paratyphoid fever can be a gastroenteritis type attack, but the course is short, the prognosis is good, and it usually recovers within 3 to 5 days. Typhoid and paratyphoid A and B are mainly characterized by high fever and systemic toxemia, which may be accompanied by abdominal pain, but less diarrhea. Typhoid or paratyphoid growth in blood or bone marrow culture can confirm the diagnosis.

5. Limited enteritis

Crohn's disease, also known as Crohn's disease, usually has a long history, with obvious onset and remission phenomena. X-ray barium meal showed that the lesion was mainly the terminal ileum, with line-shaped shadows with incomplete edges. The lesion was distributed in segments, with dilated bowel curvature in between.

6. Ulcerative colitis

The clinical manifestations are recurrent diarrhea, pus and blood, which may be accompanied by fever. The lesions are most severe in the sigmoid colon and rectum, or involve the entire colon. Colonoscopy showed intestinal mucosal congestion, edema, and ulcer formation, and the mucous membrane was brittle and prone to bleeding. Fecal cultures did not grow. X-ray barium meal in advanced cases showed the disappearance of the colonic bag, and the intestine showed a lead-like change.

7. Clostridium difficile enteritis

Both often appear after antibiotic treatment. Clostridium difficile often causes pseudomembranous enteritis, which is characterized by necrotic inflammation deep in the colon mucosa, exudative plaques, or large pseudomembranes. Etiological tests can be identified.

8. Other diarrhea

Allergic diarrhea has a history of eating fish or shrimp, or exposure to allergies. Previously, there was a history of similar drug-induced diarrhea and a history of taking laxatives; enzyme-deficiency diarrhea has a family history of genetic diseases. It is not difficult to identify through detailed inquiry about the medical history, combined with the pathogenic examination of feces.

Fungal infection treatment

With the exception of tinea capitis and onychomycosis, most fungal infections are mild and are often treated with antifungal creams. Many effective antifungal creams can be purchased without a prescription in a pharmacy. Antifungal powders are generally not used. The active ingredients of antifungal drugs are miconazole, clotrimazole, econazole and ketoconazole.

Generally, the cream is applied twice a day, and the treatment is continued until 7 to 10 days after the skin lesions have subsided. If the cream is stopped too quickly, the infection does not disappear and the rash will return.

Antifungal creams are effective only after a few days of use, during which time a corticosteroid cream can be used to relieve itching and pain. Severe or refractory infections can be treated with griseofulvin for several months, sometimes with antifungal creams. Oral griseofulvin is effective, but it can cause side effects such as headache, gastrointestinal dysfunction, light sensitivity, edema, and leukopenia. Infection may relapse after discontinuation of griseofulvin. Fungal skin infections can also be treated with ketoconazole. Like griseofulvin, oral ketoconazole has serious side effects, including liver damage.

Keeping infected areas clean and dry can help inhibit fungal reproduction and promote skin healing. Infected areas should always be washed with soap and water, and talcum powder should be sprayed after drying. Avoid using corn flour-containing powders because it promotes fungal growth.

If the fungal infection has exudate, it may be accompanied by a bacterial infection. Need to be treated with antibiotics. Apply antibiotic cream or oral antibiotics. Diluted aluminum acetate solution or Whitefield ointment can also be used to dry exudate skin.