Sporotrichosis

The Sporotrichosis Sporothrix or mycosis (also Schenk 's disease or Crohn Schenk or Rosengärtner 's disease) is a fungal disease that can affect the deep layers of the skin, the lymphatic system or the whole body. It occurs in humans, but also dogs, cats, horses, cattle, chimpanzees and rats and is known as the man on the animal and vice versa communicable disease classified as a zoonosis. The causative agent of infectious disease is Sporothrix schenckii. The sporotrichosis occurs mainly in tropical and subtropical areas before, heaped in North America, Africa and Japan, while it is very rare in Central Europe. The disease is especially evident in the formation of knots in the subcutaneous tissue, which can break and then secrete a greasy exudate. For the treatment of iodine or antifungals are used.

Cause, spread and pathogenesis

Infection occurs through direct contact with the pathogen, especially through skin wounds. Sporothrix schenckii is a ubiquitous occurring ( ubiquitous ) mushroom, which are particularly numerous in soils with decomposing organic material (humus, compost ) as seed rot ( saprophyte ) occurs. Sporothrix schenckii is a fungus dimopher: At temperatures below 30 ° C it grows in mycelial form at body temperature in yeast form.

Stick injuries by contaminated splinters, by introducing soil or plant parts in wounds caused by cats and scratch and bite wounds are frequent triggers of sporotrichosis. The pathogen can also occur in the oral cavity of healthy cats. In humans, especially staff in nurseries, gardeners and farmers are at risk.

A direct introduction into wounds but does not seem to be absolutely necessary in every case. Possibly enough the mere contact of people with the exudate of cats to infection. In addition, infected cats shed large amounts of the pathogen also with the feces.

The Sporotrichosis is primarily a single disease. 1988 were 84 Sporotrichosefälle on in the U.S., which could be attributed to Torfmullverpackungen of tree seedlings. In the years 1998 and 2004, in Rio de Janeiro, a strong accumulation of the disease, with 1503 cats, 759 people and 64 dogs were affected. In the majority of cases in humans and dogs direct contact with cats was detected.

Clinical manifestations

The skin manifests itself in the form of skin lesions, which are usually located in the vicinity of skin lesions and are not painful. Compared with antibacterial treatment, they are insensitive. This form is rare in humans before, in such cases, as " ulcerative - verrucous " lesions of the skin. In the dog occur numerous nodules ( granulomas ) in the subcutaneous tissue on which decompose ulcerated and a red-brownish exudate can secrete. Cats have often boils (abscesses ) or not accrued pus ( phlegmon ), which also decay ulcerated and show no healing tendency. Through the distinctive plaster instinct of the cat pathogen can be distributed over the body and settle beyond the original hearth.

The skin - lymphatic form ( lympohokutane form ) is caused by spread of the pathogen from the skin wounds of the lymphatic vessels and is thus a complication of skin form. This is typical of the onset sporotrichosis humans. At the point of entry arise boil -like nodes that can meltdown, and additional " satellite lesions " that are chain- like flowing along the lymphatic vessels. Typical is a lymph node swelling of the affected region.

The generalized form occurs most rarely and usually only when immunoincompetent patients, in humans, especially patients with AIDS or after organ transplantation in cats animals with leukemia or immunodeficiency syndrome. It is characterized by general and non-specific symptoms such as weakness and fever. This leads to a delocalization of the pathogen to other organs and tissues. The distribution is usually done from affected lymph nodes.

A primary lung involvement ( pulmonary form) through inhalation of conidia is possible. The prognosis is poor in such cases.

Methods of investigation

In the investigation is to ensure that the disease is contagious, even if the granulomas are not yet opened. The diagnosis is made from the nodules by a microscopic examination of exudate. The pathogens present themselves as about 2-10 microns large, cigar-shaped or round structures that can occur both within cells and free in the fluid of the exudate. Secondary bacterial infections are common. Special staining methods such as the PAS staining facilitate the diagnosis. A negative evidence in a sample includes the disease is not out yet, especially in the dog, there are usually only a few fungi in the skin nodules.

The cultivation of the organism succeeds in most cases only from samples obtained surgically from the depths of the nodules.

Most reliable is the proof of a immunofluorescence test, which indicates the possible occurrence of the pathogen still safe even with negative fungal culture.

Exclude differential diagnosis should include other bacterial and fungal diseases of the skin ( botryomycosis, nocardiosis, actinomycosis, leprosy and other mycobacterial ), pox diseases such as smallpox cats, tumors and parasites ( mange ).

Treatment

Treatment of the human

The treatment of lymphokutanen and cutaneous form of man is first daily administration of itraconazole to 2-4 weeks recommended by the latest guidelines after healing of the lesions, which is to be expected with a treatment duration of 3-6 months. If there is no response, the dose should be administered twice. Alternatively, terbinafine or saturated solution of potassium iodide can be used. Only with poor tolerance of these drugs should be resorted to fluconazole. For pregnant and lactating women, a local hyperthermia can be recommended in the skin form.

Treatment of sporotrichosis with bone and joint involvement occurs with itraconazole for at least 12 months. After two weeks of treatment, the serum level of the drug is to be determined to ensure a sufficient serum concentration. Less secure is immediate treatment with amphotericin B, which is not tolerated by all patients, and a later change to itraconazole.

The treatment of life-threatening lung infections and pronounced is also done with an initial administration of amphotericin B and the subsequent switch to itraconazole, which also shows the total duration of therapy should be at least 12 months. At less pronounced lung involvement itraconazole for at least 12 months may be administered. Surgical removal of the herd in conjunction with Amphtericin B is recommended for localized lung infection.

In the generalized form of similar guidelines. In AIDS patients may need life-long therapy.

Treatment of animals

In animals, oral administration of saturated potassium iodide solution is also cost reasons, the treatment of choice. The peroral administration of antifungal agents such as ketoconazole or itraconazole is also possible. Treatment with potassium iodide should be continued for 30 days over the disappearance of the granulomas addition. However, iodine is toxic in higher doses (→ Iodunverträglichkeit ). In case of poisoning symptoms ( nasal and ocular discharge, severe dandruff in dogs, vomiting, loss of appetite, reduced general condition or even cardiovascular failure in cats ) the treatment must be off or at least interrupted.

Literature and sources

• Chiara Noli and Fabia Scarampella: sporotrichosis. In: Practical Dermatology in dogs and cats. Schlütersche Publishing Company, 2nd edition, 2005, pp. 216-217, ISBN 3-87706-713-1
• D. W. Scott et al.: Small animal dermatology. Philadelphia: WB Saunders, 5th edition 1995, pp. 364-368.
• P. Fritsch: Dermatology and Venereology. 2nd revised. 2004 edition, Springer-Verlag, ISBN 3-540-00332-0

• Infectious disease
• Skin disease of the cat
• Skin disease of the dog
• Skin disease
• Zoonosis
• Mycosis in animals