Malasseziosis

Introduction to Malassezia Malassezia disease (infection of Pityrosporum) is a superficial stratum corneum and hair follicle infection caused by Malassezia, which can cause systemic infection. Currently, the research on Malassezia is more in-depth, mainly refers to tinea versicolor and Pityrosporum Folliculitis, so the combination of tinea versicolor and pityrosporum folliculitis, the establishment of this disease. In addition, the bacteria have a certain relationship with the onset of seborrheic dermatitis and psoriasis. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: Mycoplasma infection Staphylococcal infection

Malassezia etiology

Cause (80%):

Malassezia is one of the normal flora of the human body. It is multiplied in the hair follicle under the influence of the triggering factor, which stimulates the hair follicle to produce a large amount of desquamation, causing the hair follicle to block and produce an inflammatory reaction.

Most of the cells of Malassezia contain lipase, which is embedded in the cell wall and/or cell membrane system rich in dextran. Lipase decomposes lipids into fatty acids and provides essential nutrient sources by metabolism. Parasitic on the rich parts of the human sebaceous glands such as the chest, back, head, face and neck, is a conditional pathogen. Pityrosporum (Pityrosporum) is also known as Pityrosporum, and is classified as Mycelium by mycology. It belongs to the genus Basidiomycetes, and the genus is divided into 7 species.

1. M. furfur is a standard strain and can be divided into two new modes: oval and round; spore morphology changes greatly, and hyphae can grow.

2. M. sympodialis is the most common type on the skin, often coexisting with other species. Because the cells are small, it is difficult to observe budding. The main feature is the ability to break down esculin.

3. M. globosa is often found in tinea versicolor and seborrheic dermatitis. The colony grows slowly and the surface is deep and wrinkled. The cells are spherical and have many germ tubes, especially found in patients. Generation culture.

4. Restriction of M. restricta is named for its limited characteristics (including catalase activity), often obtained from the scalp and face, and often coexisted with other species.

5. M. pachydermatis is the only non-lipophilic Malassezia, mainly found in animal and human skin, which can cause systemic infections.

6. M. sloofiae can be found in animals and humans, mainly characterized by the inability to grow on cremophor EI and the inability to break down escin. The pathogenicity is unclear.

7. M. obtusa is very rare and has -glucosidase.

Pathogenesis

Most of the cells of Malassezia contain lipase, which is embedded in the cell wall and/or cell membrane system rich in dextran. Lipase decomposes lipids into fatty acids and provides essential nutrient sources by metabolism. Parasitic on the rich parts of human sebaceous glands such as chest, back, head, face and neck, is a conditional pathogen, high-risk population with heart and lung disease, newborn patients with severe gastrointestinal diseases, immunocompromised children and adults.

Malasseziosis prevention

For patients with superficial and follicular infections, pay attention to hygiene, bathe and change clothes, prevent excessive sweating, be exposed to frequent exposures, avoid applying oily substances on the body, and avoid wearing tight and airtight underwear.

Malasseziosis complications Complications Mycoplasma infection with staphylococcal infection

The complications of this disease are mainly caused by bacterial infections of other tissues. Malassezia belongs to the genus Fungi, often accompanied by obvious itching of the skin. Therefore, the infection is often caused by scratching, and the other nails are scratched due to contaminated nails. The skin can be transplanted to the fungus to cause infection of the skin fungus. Therefore, the fungus examination of the whole body skin and nails should be carried out clinically after the disease is clarified.

Symptoms of Malassezia Symptoms Common symptoms Joint pain scaly nausea Respiratory failure chills pustules weakness, lethargy, granuloma, itching

1. tinea versicolor: tinea versicolor is a superficial infection of the skin, the damage is mostly gray-yellow, brown or dirty brown or even gray-black rash. If bathing frequently, it can be light red, the rash starts to appear as a cap The size of the needle is gradually increased. For example, the number of lentils or small fingernails is large, and the number is gradually increased. It can fuse with each other, invade the vast surface of the skin, and the edges are clear, the surface is slightly shiny, there is bran-like scales when scratching, and the symptoms are alleviated or When it is still in the winter, it will reduce the color spots, and it will be sent again the next year. After slow, it will occur in adults, and it is more common in men.

2. Pityrosporum folliculitis: more common in young and middle-aged, the average age of onset is about 30 years old, more men than women, rashes are small miliary dark red papules or small cystic pustules, diffuse scattered distribution, good hair The site is the front chest, back, shoulders, neck, a few found in the forearm, calves and face, consciously moderate or mild itching, and some with burning and tingling, a few cases can be combined with tinea versicolor.

3. Systemic infection: Clinical manifestations are related to age.

(1) Infants under 1 year old: severe basic diseases are low birth weight premature infants, respiratory distress, bronchial dysplasia, aspiration pneumonia, congenital heart disease, necrotic enteritis, abdominal deformity, etc., sudden rise in body temperature, breathing Suspension, bradycardia is a common manifestation, and pneumonia, interstitial pneumonia, respiratory distress, lethargy, malnutrition and respiratory failure can be seen.

(2) Children and adults: severe underlying diseases are aplastic anemia, leukemia, small bowel resection, hemorrhagic necrotizing pancreatitis and organ tumors, etc., many sudden fever, chills, nausea, vomiting, muscle weakness Such symptoms may include cough, unstable body temperature, and joint pain.

Examination of malasseziosis

Malasseziosis can be studied by mycology:

1) Direct microscopic examination: direct staining with lactic acid phenol aniline blue can be found in clusters or scattered spores.

2) Fungal culture: A pale yellow, creamy yeast-like colony can be cultured with a sandcastle agar containing oil.

Histopathological examination: spores, round, oval or curved in the shallow and middle part of the stratum corneum of superficial infection, GMS, PAS or toluidine blue staining can be more clear, there may be lymphocyte infiltration in the dermis.

Folliculitis is examined by follicular papules. PAS staining has round or oval spores and blastospores in the enlarged hair follicle cavity. It is deep reddish red and aggregates into cells. There is inflammatory cell infiltration around the upper and adjacent dermal blood vessels.

Diagnosis and identification of malasseziosis

diagnosis

For superficial and follicular infections, according to clinical features, fungal examination, golden yellow fluorescence under Wood light, diagnosis is not difficult. For systemic cases, all of the above-mentioned underlying diseases are treated with parenteral high-nutrition treatment, and acute signs of infection appear clinically. When diagnosed, it should be confirmed by mycological examination.

1. Mycological examination: (1) Direct microscopic examination: direct staining with lactic acid phenol aniline blue, clusters or scattered spores can be found. (2) Fungal culture: A yellowish, creamy yeast-like colony can be cultured with a sandcastle agar containing oil.

2. Histopathology: superficial infection of the skin in the shallow and middle part of the stratum corneum spores, round, oval or curved, GMS, PAS or toluidine blue staining can be more clear, there may be lymphocytic infiltration in the dermis, folliculitis Follicular papules examination, PAS staining in the enlarged hair follicle cavity with round or oval spores and blastospores, deep red rose, gathered into a pile, inflammatory cell infiltration around the upper and adjacent dermal blood vessels, systemic infection Mainly manifested as moderate, small vasculitis changes, thrombosis and embolism, may have granuloma formation and infarction.

TCM Syndrome: Trichogram: Chinese medicine believes that the disease is invaded by rheumatism due to hot body, and it is caused by foreign worms and stagnation. It is also caused by sweaty clothes, drowning the skin, regaining the sun, and dampness. Caused by stagnation of sputum, it is equivalent to Chinese medicine purple and white hurricane, such as "Ji Zong Jin Jian · Surgical Heart Law" records: "Purple and white hurricane without itching pain, white due to qi stagnation purple blood coagulation, hot body wind invading the temperature, hairy Occlusion of the plaque."

Differential diagnosis

Superficial infections sometimes need to be differentiated from seborrheic dermatitis, pityriasis rosea, vitiligo, anemia, chloasma, red sputum, etc., folliculitis should be associated with acne vulgaris, bacterial folliculitis, hair follicle dermatitis and acidophilic abscess Identification of sexual folliculitis, different species of Malassezia should be identified by biochemical experiments.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.