OVERVIEW
This disease is a chronic infection of the skin, subcutaneous tissues and nearby lymphatic vessels caused by Schenkosporium filamentum, which can cause pus, ulceration and exudation. Moist environments and decaying grasses favor the growth of the organism, which invades when the skin is broken, and manifests differently depending on the patient’s history of exposure to the organism and immune status.
Questions you may be concerned about
Is sporotrichosis contagious?
Sporotrichosis is contagious to others.
Sporotrichosis is a chronic infectious disease caused by sporotrichosis infection of the skin, mucous membranes and their surrounding lymphoid tissues, and the main symptoms include papules, pustules, warty nodules, and abscesses and ulcers. Sporotrichosis is a zoonotic disease with a certain degree of contagiousness. Animals and humans carrying sporotrichosis, as well as contaminated objects, may become the source of infection.
Sporotrichosis is generally difficult to self-cure, patients can use itraconazole, terbinafine, potassium iodide, fluconazole and other drugs under the guidance of the doctor for treatment, for fixed lesions of sporotrichosis patients, drug treatment is ineffective can be surgical treatment.
It is recommended that patients strictly follow the doctor’s instructions to use medication, actively cooperate with the doctor’s treatment, pay attention to the living environment and personal hygiene, keep the skin clean and dry, during the treatment period, patients should avoid eating spicy, stimulating food, quit smoking and alcohol.
Causes
Sporotrichosis is a chronic infection of the skin, subcutaneous tissue and nearby lymphatic vessels caused by Schenck (Schenck) sporotrichum.
The disease is primarily contracted through damaged skin or mucous membranes, the upper respiratory tract, and the digestive tract.
Sporotrichosis primarily invades the skin, mucous membranes, and local lymphatic system, causing granulomatous damage. Intrapulmonary lesions are initially bronchitis and bronchopneumonia in a segmental distribution.
Symptoms
1. Cutaneous lymphatic type
Most common, the fungus is implanted by the trauma, and small, hard, pushable, painless subcutaneous nodules appear locally, which are red, purple or black, and sometimes initially ulcerated. Prevalent in the finger or wrist, the damage is arranged along the lymphatic vessels, self-conscious symptoms are not obvious.
2. Fixed type
Prevalent in the face, neck, trunk and other places, the damage is ulcerated, wart-like or infiltrating granuloma, sometimes surrounded by satellite-like damage.
3. Skin and mucous membrane type
Less common, occurring in the mouth, throat or nose, initially erythema, ulceration or purulent damage, later become granulomatous, redundant or papillomatous damage.
4. Disseminated sporotrichosis
Bone, periosteum and synovial sporotrichosis, ocular sporotrichosis, systemic sporotrichosis and sporotrichosis meningitis can occur.
5. Pulmonary sporotrichosis
Pneumonic sporotrichosis is mainly caused by inhalation of spores, with symptoms of cough and fever. It also presents with nodular damage, thin-walled cavities, fibrosis and pleural effusion.
Examination
1. Histopathology
Septic inflammation formed by histiocyte-dominated granulomas and neutrophilic infiltration. PAS staining in abscesses and multinucleated giant cells can sometimes find spores or stellate bodies, and cigar-shaped vesicles and stellate bodies can be seen in typical cases.
2. Laboratory examination
Specimen collection: pus or blood is collected from the black spots of skin damage and unbroken nodules, and other sputum, blood, bone marrow, cerebrospinal fluid or skin biopsy, visceral tissues. ② When examined directly, spores are easily confused with other structures, especially when the number of spores is small, and are often difficult to recognize. Therefore, culture should be done to confirm the diagnosis. ③ Shah agar medium, 37 ℃ and 25 ℃ colony morphology is the same, but some fixed sporotrichum lesions in the strain can not grow at 37 ℃, it is best to be placed in two incubators to be cultivated. ④ Pus or tissue fungus culture with sporotrichum growth. ⑤ When penicillin is added to the culture medium, it can stimulate the growth of Sporothrix.
3. Pathologic examination
(1) Direct microscopic examination: take sputum, pus or biopsy tissue and smear directly, make Gram stain or PAS stain, in the multinucleated cells or large mononuclear cells or around the cells, there are Gram-staining positive, round or shuttle-shaped, 2-5μm in diameter small spores. Occasionally, mycelium and stellate bodies are seen.
(2) Bacterial culture: ① glucose peptone agar medium, room temperature, that is, the growth of bacteria. 6 days after the colony 0.5cm diameter size, gray-brown membranous colonies, slightly higher than the surface of the culture. 10 colonies up to 1.5 ~ 2.0cm diameter, the surface of the 3 bands, the edge of the membranous white halo; in the middle of the band of dark brown; the central bulge, wrinkled, uneven, there are a small number of thorns between the mycelium. 2 weeks. The colonies of 2 weeks were dark brown, with sunken edges. When sampling and examination, the colony was very sticky and not easy to remove. Microscopic examination showed elongated separated hyphae with a diameter of 2μm. Conidiophores grew out from both sides of the hyphae, at right angles to the hyphae, and at the tip there were 3-5 groups of pear-shaped conidia (2-4)μm×(2-6)μm in size, arranged in a plum blossom-like pattern. ② Cystine dextrose blood agar or brain heart infusion dextrose blood agar base, 37 ℃ culture, white colonies, microscopic examination of round or spindle-shaped spores, sometimes outgrowth of buds, positive Gram stain. ③Electron microscopy showed round or oval microspores and elongated segregating mycelial spores, high electron density, radial shape, dark center, coat attached to the outside of the cell wall. The cell wall of the mycelium was of medium electron density, and the cytoplasm was microscopic granular with mitochondria, endoplasmic reticulum and vacuoles. The mode of germination was endospore type, the mycelium mechanically broke into mycelial fragments during biphasic migration, and polymorphism was observed in conidium formation. In the mycelial phase, pseudo-axial conidiophore was seen, and multiple terminal conidia were formed.
4. Immunological examination
(1) Skin test: Intradermal injection of 0.1 ml of 1:1000 bacterial vaccine, 24-48h nodules are positive.
(2) Serologic examination: serum precipitin and agglutinin positive (titer increase), positive complement binding test.
5. X-ray examination
Different types of lesions, chest X-ray performance varies: ① bronchopneumonia type: patchy, nodular shadows with focal distribution, or diffuse infiltration. ② chronic cavity type: translucent areas appear in the original inflammatory infiltration shadow, i.e. thin-walled cavity formation. (iii) Lymph node enlargement: the shadow of hilar and/or mediastinal area is enlarged and thickened, which can be unilateral or bilateral. When accompanied by bronchial obstructive lesions, restrictive emphysema, or restrictive pulmonary atelectasis may occur.
Diagnosis
Based on the clinical manifestations of the disease, combined with fungal examination, fungal culture and histopathologic examination, the diagnosis is generally not difficult. Histopathology shows purulent and granulomatous inflammation of the dermis and subcutaneous tissues, and it is difficult to visualize microorganisms, which can be seen by PAS staining when large numbers of pathogens are present. However, it should be differentiated from warty skin tuberculosis, coloring mycoses, budding mycoses, and anthrax.
Treatment
Systemic treatment is the mainstay, simple local treatment has no obvious effect.
1. Systemic treatment
(1) Itraconazole It is effective in the treatment of cutaneous lymphangiectasia and fixed sporotrichosis, and the course of treatment is 3-6 months.
(2) Potassium iodide has no inhibitory effect on fungi, and may play a role by affecting the immune response of patients. Treatment is effective, but be aware of side effects such as gastrointestinal discomfort and suppression of the thyroid gland.
(3) Amphotericin B For severe and disseminated sporotrichosis.
2. Local treatment
(1) 2% potassium iodide solution or 10% potassium iodide ointment is used externally. After the damage subsides, it should be used continuously for about 1 month to prevent recurrence.
(2) Local liquid nitrogen therapy, especially for isolated small damage.
(3) Local warming therapy can control the fungal growth in the tissue, and the treatment temperature should reach 40℃～43℃. Pregnant women or patients with severe liver or kidney disease can be given warm therapy
Prevention
Pay attention to protect the skin, do not touch rotting grass, do not prick the skin.