Cat Fault Scratches: Causes, Symptoms, Diagnosis, Treatment

Cat scratch disease (felinosis, benign lymphatic drainage, cat scratch disease) is an acute zoonotic infectious disease with a contact and transmissible mechanism of transmission of the pathogen, characterized by lymphadenitis, primary affect in the form of a papula, in some cases - conjunctivitis, angiomatosis and liver damage.

ICD Code 10

A28.1. Fever from cat scratches.

Epidemiology of cat scratch disease

The source of the causative agent for humans is cats, more often kittens. Cats easily become infected with B. Henselae by bites of fleas Cfenocephalides felis. In the body of the cat, B. Henselae persists for more than a year, without causing disturbances of health, is a part of the normal microflora of the oral cavity. Cats may have asymptomatic bacteremia with a duration of up to 17 months (follow-up period), which ends after a course of antibiotic therapy. Infection of a person occurs during close contact with a cat (bite, scratching, licking) with damage to the skin or conjunctiva of the eye. Fleas can also attack a person, carrying out a transmissive transmission of the disease. Approximately 90% of the patients with a history have instructions for contact with cats, contacts with proteins, dogs, goats, pincers of crabs, barbed wire are also described. The susceptibility is low.

Children and people who are less than 20 years old usually fall ill, more often in the fall and winter. Sometimes there are family flashes. Patients do not pose a danger to others. After the transferred disease, persistent immunity develops, but relapses of the disease in adults are described.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]

What causes cat scratch disease?

The disease of cat scratch is caused by Bartonella henselae B. Quintanae of the Bartonella family - a mobile small gram-negative rod of 0.3-0.5x1.0x3.0 μm in size. Has one flagella, is capable of intracellular parasitization.

In sections from infected tissues, the rods can be curved, pleomorphic, often grouped into compact clusters (clusters). They are colored according to Romanovsky-Giemsa, and in biopsy specimens from tissues - with dyes using silver (according to Warthing-Starry). In immunochemical studies, the acridine orange dye is used. Bacteria have a clearly structured three-layered shell containing up to 12 proteins with a molecular weight of 28-174 kD. Propagation of the pathogen occurs by simple transverse division.

B. Henselae outside the human body can be cultivated in feline fleas, as well as on semi-liquid or solid nutrient media enriched with 5-10% of human or animal blood (with a longer, more than 15-45 days, aging of sown agar plates under optimal conditions ).

Factors of B. Henselae pathogenicity have not been studied.

Pathogenesis of cat scratch disease

The spread of the pathogen from the site of the entrance gates occurs lymphogenically and hematogenously. B. Henselae with the flagella first attach to the surface, and then penetrate into the erythrocytes and endothelial cells of the vessels and endocardium, and further stimulate the proliferation of endothelial cells and the growth of small vessels (capillaries), which can lead to the development of angiomatosis.

Usually, with cat scratch disease, the site of the entrance gate determines the localization and form of the process (typical forms are manifested by primary affect and regional lymphadenitis, atypical forms are ocular, CNS or other organs are affected). Bacillary angiomatosis can be isolated as a separate generalized form characteristic of patients with HIV infection and other types of immunodeficiency.

In places where the pathogen is attached to sensitive cells, microorganism clusters are formed with the development of inflammation and proliferation of endothelial cells and adjacent tissues. Part of the endothelial cells necrotic. As a result, lymphadenopathy develops (mainly with typical forms of cat scratch disease), angiomatosis or a combination of them with simultaneous damage to bone marrow cells and erythrocytes. Around the sites with "swollen" ("epithelioid") cells, neutrophils and eosinophils are grouped. Bacteria are found in erythrocytes, endothelial cells of blood vessels, spleen, lymph nodes, liver, bone marrow, skin. In the heart valves in patients with severe endocarditis, numerous vegetations consisting of fibrin and platelets (microscopically determine the masses of extracellular pathogens and superficial inflammatory infiltrates on the valve flaps-perforation appear.) In individuals with immune deficiency in the formation of chronic bacteremia, part of the B. Henselae population in inflammatory infiltrates is localized intracellularly.For bacillary angiomatosis, the morphological basis of the disease is local proliferation of swollen their endothelial cells protruding into the lumen of the vessels, therefore, with the primary lesion of the skin on its various parts, single or multiple (perhaps more than 1000) peerless papules and hemangiomas (often with the formation of the foot) rising above the skin level and sometimes reaching the size of the lymph nodes. With a deeper subcutaneous arrangement of vascular proliferation, knotty plexuses with sizes up to several centimeters are formed. Often necrosis is possible, with slight damage - bleeding. Microscopy of biopsy specimens stained using silvering reveals perivascular eosinophilic aggregates with areas of massive accumulations of bacteria. A similar picture is observed with lesions of internal organs; possibly the development of bone necrosis.

What are the symptoms of cat scratch disease?

The cat scratch disease has an incubation period that lasts from 3 to 20 (usually 7-14) days. There are typical, eye forms of the disease and bacillary angiomatosis. Typical forms are characterized by the development of primary affect and regional lymphadenitis. A small, painful papule from 2 to 5 mm in diameter with a rim of skin hyperemia appears on the site of the wound that has already healed after a bite or scratch, then it turns into a vesicle or pustule, and then into a small sore (not always) covered with a dry crust. The papule occurs in 60% of patients, but by the time of going to the doctor the inflammatory reaction disappears, the crust can fall away, the scratch can heal, so the primary affect is often not detected. Primary affect is localized more often on the wrist or forearm, less often on the face, neck, in the clavicle, on the lower leg. The general condition is not violated. At half of patients in 1 month and more there is a suppuration of lymph nodes, they are soldered to the skin; there is congestive hyperemia, fluctuation; a fistula is formed, from which within 2-3 months. Pus is released, then healing takes place with the formation of a scar. After 15-30 days after infection, regional lymphadenitis develops - a constant and sometimes the only symptoms of cat scratch disease. Often amazed axillary, ulnar, less often - parotid and inguinal lymph nodes. They reach a diameter of 3-5 cm or more, are usually dense, painless, mobile; are not welded to each other, with the skin of the city by surrounding tissues. The enlargement of lymph nodes lasts from 2-4 months to a year. In the process, one to several (10-20% of cases) of lymph nodes of one group are involved. Bilateral lymphadenopathy is rarely found. At the same time, the lymph nodes reach a diameter of 2-3 cm. They are dense, painless, do not swell. Symptoms of cat scratch disease: intoxication, fever, chills, weakness, headache, etc. Are observed in 30-40% of patients. Body temperature can rise to 38-41 ° C, be paroxysmal, persist for 1 to 3 weeks. Characterized by weakness, fatigue, headache. Often the liver and spleen increase, even in the absence of a febrile reaction. The disease of cat scratch is wavy. The defeat of the nervous system is recorded in 5-6% of patients. It develops during severe illness after 1-6 weeks after the onset of lymphadenopathy, accompanied by severe fever, intoxication and can manifest itself in the form of serous meningitis with low lymphocytic pleocytosis of the cerebrospinal fluid, radiculitis, polyneuritis, myelitis with paraplegia. Complications of severe disease - thrombocytopenic purpura, pneumonia, myocarditis, abscess of the spleen.

If the entrance collar serves as a conjunctiva, the eye form of the disease develops (3-7% of patients), reminiscent of conjunctivitis Parino. As a rule, one eye is affected. Against the backdrop of fever and intoxication, there is a pronounced edema of the eyelids, conjunctiva, chemosis develops. On the conjunctiva of the eyelids (or only the upper eyelid) and the transitional fold, gray-yellow nodules appear, which often ulcerate. Detachable from the conjunctival cavity mucopurulent. The cornea is usually not affected. The lymph node located in front of the earlobe increases significantly and subsequently becomes swollen with the formation of fistulas, after which cicatricial changes remain. Sometimes, the submandibular lymph nodes also increase. Inflammatory changes persist 1-2 weeks; the total duration of the disease ranges from 1 to 28 weeks.

In most patients, cat scratch disease occurs in the above described typical form. Sometimes the course of the disease has an unusual nature and is accompanied by a systemic lesion of the body, which is manifested by polymorphism of the clinical picture. There may be a variety of rashes, thrombocytopenic purpura, damage to bones, joints, liver, spleen, development of visceral lymphadenopathy. Such a course is mainly characteristic for persons with marked immunity damage and is well described in patients with HIV infection. These symptoms of cat scratch disease are often identified as "bacillary angiomatosis," which can be described as a generalized form of benign lymphoreticulosis. In this case, angiomatosis of the skin develops in the form of single or multiple painless papules of red or purple color, from point to larger, randomly located on various parts of the body, limbs, head and face. In the future, papules increase (up to the size of lymph nodes or small tumors, resembling hemangiomas) and can rise, like fungi, over the skin. Some of them are suppressed and resemble pyogenous granulomas. Sometimes lesions develop in the form of plaques with the center of hyperkeratosis or necrosis. Many vascular outgrowths bleed. With a deeper subcutaneous arrangement of vascular proliferation, knotty formations appear, the dimensions of which can reach several centimeters. They are also located on any part of the body, often diffuse throughout the body or head. It is possible to combine superficial and more deeply located subcutaneous vascular overgrowths, as well as damage to the vessels of internal organs and bones, down to pronounced osteolysis. Bacillary angiomatosis occurs with fever, marked by intoxication. Characteristic is a significant increase in ESR, leukocytosis.

In the independent form of the disease, some authors isolated bacillary purpura hepatitis (bacillary peliosis hepatitis), but more correctly this form is regarded as a variant of the flow of bacillary angiomatosis, in which the signs of lesion of the liver parenchyma predominate. Due to the defeat of small blood vessels of the liver, cystic formations are formed in them, overflowing with blood, which squeeze the liver cells. As a result, blood stasis develops and liver function is impaired. Among the complaints are nausea, diarrhea, bloating in the background of fever and chills. At the examination, hepatosplenomegaly, anemia, thrombocytopenia, an increase in the activity of hepatic enzymes in the blood serum, and histologically in the liver biopsy samples - multiple enlarged capillaries and blood-filled cavernous spaces in the parenchyma.

How is cat scratch disease diagnosed?

Diagnosis of cat scratch disease is based on the symptoms of the disease: a primary affect in the history that arose after contact with the cat for several days or weeks before the onset of the disease, an increase in the regional lymph node.

The diagnosis can be confirmed by the results of bacteriological analysis of the blood, as well as histologically: examining the tissues of the papule or lymph node, staining them using silver by Warthing-Starry in order to determine the accumulation of bacteria. In bacillary angiomatosis, nodular accumulations of the pathogen are found in massive perivascular eosinophilic infiltrates. With electron microscopy, pleomorphic rods with a three-layer Gram-negative membrane are clearly visible. Serodiagnostics are used: it makes it possible to detect antibodies in the blood (and build up their titer) to a specific antigen of the microorganism (RIF and ELISA). The molecular genetic methods using PCR have been developed.

Differential diagnosis of cat scratch disease

Differential diagnosis of cat scratch disease with tuberculosis of lymph nodes, tularemia, bacterial lymphadenitis and other diseases is carried out. In all cases, it is necessary to take into account a characteristic anamnesis. With bacillary angiomatosis or severe systemic lesions, differential diagnosis of cat scratch disease is also performed with Kaposi's sarcoma (mandatory histological examination).

Differential diagnosis of cat scratch disease

Symptom	Cat scratch disease	Tuberculosis of lymph nodes	Cutaneous bubonic tularemia	Bacterial lymphadenitis
The lymph nodes	Regional lymphadenitis, tenderness, edema of skin hyperemia, unilateral process	The lymph nodes of the cervical group are increased more often, Fistula formation is possible	Regional lymphadenitis	Sharp tenderness, hyperemia of the skin, fluctuation, lymphangitis
Primary affect	Papula or scratch a few days before lymphadenitis	Absent	Painless sore with scarring	Absent
Rash	With the development of bacillary angiomatosis, single or multiple painless papules of red or purple from point to very large, which subsequently increase. Nodal elements are possible, bleeding	Absent	In the midst of the disease, a rash of an allergic nature (erythema, petechiae, vesicles, followed by otrubrious or lamellar ecdysis	Absent
Fever, intoxication	Possible with suppuration of the lymph node	None	Pronounced from the 1st day of illness	Possible with suppuration of the lymph node

[11], [12], [13], [14], [15]

Indications for consultation of other specialists

With the development of bacillary angiomatosis for differential diagnosis with Kaposi's sarcoma and other skin lesions, consultation of the dermatovenerologist is indicated, with suppuration of the lymph node - consultation of the surgeon, with the eye form of the disease - consultation of the ophthalmologist. With the development of endocarditis in some patients, even with prolonged (4-6 months) intravenous administration of antibiotics, there may be a need for prosthetic valves.

Indications for hospitalization

Indications for hospitalization - the need for differential diagnosis with lymphadenopathy of another etiology, bacillary angiomatosis.

How is cat scratch disease treated?

Diet and diet

Home mode.

In a special diet is not necessary.

[16], [17], [18], [19], [20], [21], [22]

Medicamentous treatment of cat scratch disease

In typical cases, symptomatic treatment of cat scratch disease is performed, with suppuration of the lymph node it is punctured to remove pus. To open the lymph node is not recommended, since it is possible to form fistulas that do not heal for up to a year or more. In clinical practice, in particular, with suppuration of the lymph nodes, bacillary angiomatosis, ciprofloxacin is used at 0.5-1.0 g twice daily, azithromycin 0.5 g once daily, rifampicin 0.9 g / day in two doses. The duration of antibiotic therapy is 2-3 weeks. Doxycycline, tetracycline, roxithromycin, norfloxacin are also used. In the defeat of bones recommend the combined use of fluoroquinolones and rifampicin. Patients with HIV infection, in addition to antibiotics, are assigned antiretroviral treatment of cat scratch disease (according to indications).

Approximate terms of incapacity for work

Terms of incapacity for work depend on clinical recovery.

[23]

Clinical examination

Clinical examination is performed only for patients with HIV infection.

[24], [25], [26], [27], [28]

How to prevent cat scratch disease?

The disease of cat scratch does not have a specific prevention. The removal of claws is shown, especially in kittens, the disinsection of cats. At care of cats it is necessary to observe rules of personal hygiene. Cats should not be let out into the street. A wound from a bite, scratches process tincture of an iodine or brilliant green.