Overview
Hansenula polymorpha is an infectious disease caused by invasion of the human body, most often manifested as skin papules or pustules at the site of injury, swollen lymph nodes, fever, anorexia, malaise, etc. According to the condition, the main anti-infective and symptomatic treatments are self-limiting, and the prognosis is good.
Definition
Benign lymphoreticulocytosis, also known as cat-scratch disease, is an infectious disease caused by the invasion of Hansenula polymorpha into the human body, and the course of the disease is self-limiting, i.e., it can be cured spontaneously [1].
Hansenula polymorpha can be infected through close contact with infected cats, or by their licking, scratching, or biting.
Cat-scratch disease is characterized by skin lesions at the site of injury and enlarged lymph nodes, which may be accompanied by fever, anorexia, malaise, nausea, and vomiting [2].
The diagnosis of the disease can be confirmed based on a history of cat contact, scratching and biting, and the detection of Hanseniasis in combination with pathogenetic testing.
Typing
It can be divided into two types based on clinical manifestations.
Typical cat scratch disease
Also known as cat scratch lymphadenitis.
Symptoms are dominated by skin lesions such as erythema, papules and blisters at the site of injury, with mild systemic symptoms such as fever, malaise and anorexia.
The disease is mild and the skin lesions are shallow, and most patients can recover gradually.
Atypical cat scratch disease
Atypical Cat Scratch Disease refers to the cat scratch disease with the manifestation of involvement other than lymph nodes.
It can be divided into generalized cat scratch disease, central cat scratch disease, ophthalmic cat scratch disease, musculoskeletal cat scratch disease, liver and spleen cat scratch disease, and mammary cat scratch disease according to the involved parts.
It is mostly caused by the spread of Hansenula polymorpha to the whole body through the blood and lymphatic circulation.
It is often accompanied by systemic symptoms and lasts for a long time. Invasion of different tissues can cause corresponding symptoms.
Incidence
Cat-scratch disease is mostly disseminated, and the onset of the disease is concentrated in the fall and winter, i.e. from July to January.
Cat scratch disease is distributed all over the world. Since the disease is not a legally recognized infectious disease in China, the exact number of cases is not known.
Causes
Causes
Cat-scratch disease is caused by Hansenula polymorpha infection, and the basic conditions leading to the epidemic are the following three aspects.
Source of infection
Cats with Hanseniasis are the main source of infection for this disease.
Means of transmission
Close contact with or licking, scratching, or biting of cats carrying Hansenula polymorpha is the main means of transmission.
Secondly, it can also be transmitted through the bite of blood-sucking arthropods such as fleas and lice on cats.
Susceptible Population
The population is generally susceptible, but children and adolescents are more susceptible.
Pathogenesis
After invading the human body, Hansenula polymorpha can cause a delayed hypersensitivity reaction in lymph nodes and skin, and its mechanism may be related to the dysfunction of immune recognition induced by Hansenula polymorpha and tissue-soluble antigens in the vascular wall of the damaged site [3].
The invasion of Hansebatom bodies into the skin can cause erythema, papules, pustules and other skin damage.
Hansebatone bodies can infect lymph nodes, leading to lymph node granulomas, lymph node fibroblast hyperplasia, and abscess development.
Hanseniasis can spread throughout the body through the lymphatic system or bloodstream, causing damage to multiple organs throughout the body.
Symptoms
Main Symptoms
Symptoms of cat-scratch disease are related to its affected areas and mainly include the following.
Skin manifestations
In most patients, 3 to 10 days after being scratched, maculopapular rash, erythema, herpes, pustules, etc. can appear on the skin of the injured area, mostly on the face, hands and feet, calves and forearms, which can last for about 1 to 3 weeks.
After healing of the skin lesions, scarring or crusting is seen to remain on the affected area [4].
Lymph node enlargement
Lymph node enlargement, accompanied by fever and lymph node pain, can appear 2 weeks after scratching, and the symptoms are firstly seen on the same side of the limb that is scratched or bitten, followed by the neck, axilla, submandibular, groin, etc. The symptoms are self-limiting, and most patients have the symptoms of lymph node swelling.
It is self-limiting, with symptoms lasting 6 to 9 weeks in most patients and more than 6 months in a few.
Other symptoms
Systemic symptoms
Low-grade fever, headache, malaise, chills, anorexia, nausea and vomiting are the main symptoms.
Ocular manifestations
Ocular symptoms are relatively rare and are most commonly seen in children.
Parrino’s oculo-glandular syndrome is a common manifestation of typical cat scratch disease, which may be characterized by conjunctival congestion, redness and swelling, accompanied by increased ocular discharge.
It may also cause Leupold’s stellate retinopathy, which is characterized by sudden, unilateral, painless loss of vision.
Neurologic manifestations
Rarely, the incidence is only about 2%, which may cause encephalitis, with seizures, headache, delirium and coma.
Liver and spleen manifestations
Liver and spleen enlargement, fever, abdominal pain, etc. Multiple hypoechoic and hypodense areas in the liver and spleen can be seen on imaging.
Musculoskeletal manifestations
Knee, wrist and ankle joints are often involved, with myalgia and arthralgia as the main manifestations.
Breast manifestations
Isolated lumps are the main manifestation, often accompanied by enlarged lymph nodes in the axilla of the same side.
Cardiac manifestations
Infective endocarditis may be triggered, causing fever, shortness of breath, chest tightness and fatigue.
Kidney manifestations
Glomerulonephritis may occur, which is manifested by hematuria, fever and enlarged lymph nodes.
Lung manifestations
May cause pneumonia and pleural thickening, with symptoms such as cough and shortness of breath.
Consultation
Department of Medicine
Department of Infectious Diseases
When there is a history of close contact with cats, after being scratched, licked or bitten by cats, skin rashes at the site of injury, swollen lymph nodes, etc., it is recommended to consult the Department of Infectious Diseases in a timely manner [5].
Dermatology
When there are obvious skin papules and herpes, consult the dermatology department.
Preparation for medical treatment
Consultation: registration, preparation of information, common questions
Tips for medical consultation
A full body physical examination and imaging tests may be required during the visit, so loose clothing should be worn, and clothing made of metal should be avoided.
If you have a fever before the visit, you can first apply physical cooling, such as warm towels on the forehead or underarm wipes.
Preparation Checklist
Symptom checklist
Particular attention should be paid to the time of onset of symptoms, special manifestations, etc.
Are there skin lesions, papules, pustules, etc.?
Is there fever, headache, etc.?
Are there masses on the superficial skin, neck, armpits, etc.?
Is there any loss of appetite, fatigue, abdominal pain, etc.?
When did the above symptoms appear?
List of medical history
Do you have a cat at home?
Have you recently been in close contact with cats?
Have you been scratched, bitten or licked by a cat recently?
Checklist
Examination results in the last six months, which can be brought to the doctor’s office
Laboratory tests: blood tests, etc.
Imaging tests: chest or abdominal CT, etc.
Medication list
Medication used in the last 1 week, if there is a medicine box or package, you can bring it to the doctor
Topical skin medication: ketoconazole cream, compound dexamethasone acetate cream, etc.
Antipyretics: ibuprofen, acetaminophen, etc.
Diagnosis
Diagnosis is based on
Medical History
Patients with this disease may have the following epidemiologic history.
Close contact with a cat.
Recent cat scratches, bites, or licks.
Clinical manifestations
The main manifestations are skin blisters and other damage at the site of injury, enlarged and painful lymph nodes, which may be accompanied by fever, anorexia, malaise, nausea and vomiting.
Laboratory Tests
Blood count
The total number of leukocytes may be reduced in the early stage, and when accompanied by suppuration of lymph nodes, the total number of leukocytes may be mildly elevated, and neutrophils are increased.
Pathogen culture and isolation
Hanseniasis can be isolated and cultured from the patient’s blood, lymph node pus, and the site of primary skin damage [6].
Serologic tests
Indirect immunofluorescence antibody test: specific antibody to Hansenula polymorpha in the patient’s serum with a potency of ≥1:64 is considered positive.
Enzyme-linked immunosorbent assay: detection of positive anti-Hansenbaum’s body IgM antibody.
Molecular biology examination
Using in vitro DNA amplification technology to detect Hanseniasis in lymph node biopsy specimens and pus, detection of Hanseniasis DNA can confirm the diagnosis [7].
Skin test
Lymph node puncture fluid was taken, which was heated and sterilized and injected into the skin of the palmar side of the forearm, and the appearance of a hard nodule with a diameter of ≥5 mm in 48 hours was considered positive.
Pathologic examination
The skin and lymph nodes of the lesion site were taken for pathological examination, and Warthin-Starry silver immersion color found black, different sizes, polymorphic short rod-shaped bacilli, which had diagnostic significance.
Imaging examination
Abdominal CT
In patients with cat-scratch disease accompanied by hepatic and splenic lesions, hepatosplenomegaly is seen on abdominal CT.
Diagnostic criteria
The diagnosis of cat-scratch disease should be made by combining epidemiologic history, clinical manifestations, and laboratory tests, and the diagnosis can be made if three of the following criteria are met.
History of contact with felines (with or without visible skin lesions).
Exclusion of other possible causes of lymph node enlargement and a positive polymerase chain reaction (PCR) of pus obtained from aseptic puncture of a lymph node and/or a CT scan that reveals hepatic or splenic lesions.
Antibody titer ≥ 1:64 by immunofluorescence analysis (IFA).
Pathohistological examination suggestive of granulomatous inflammation or Warthin-Starry silver-impregnated color finding of mycobacteria.
Differential Diagnosis.
Hanseniasis can cause skin, lymph node, and systemic associated symptoms, which lack specificity and need to be differentiated from similarly symptomatic diseases under medical supervision.
Symptoms of lymph node enlargement caused by Hanseniasis need to be differentiated from lymph node tuberculosis, lymph node granuloma, histiocytic necrotizing lymphadenitis, and Hodgkin’s lymphoma [8].
Skin symptoms such as rash caused by hansenbachia need to be differentiated from scrub typhus.
Lymph node tuberculosis
Similarities: Both present with enlarged lymph nodes with mild localized swelling and pain.
Differences: Lymph node tuberculosis is a chronic inflammation of the lymph nodes caused by Mycobacterium tuberculosis, and usually does not have symptoms of skin lesions, whereas cat-scratch disease can be seen in the skin lesions with red rashes, pustules and other symptoms. It can be differentiated by appropriate pathogenetic tests.
Scrub typhus
Similarities: Both can cause fever, rash, swollen lymph nodes and other symptoms.
Differences: Scrub typhus has a rapid onset of symptoms, often accompanied by fever, body temperature can rise rapidly to 39 ℃, can be accompanied by chills, severe headache, generalized pain, drowsiness, loss of appetite, nausea and vomiting, etc., while the cat scratching disease systemic symptoms are milder. It can be differentiated by the corresponding pathogenetic examination.
Treatment
Treatment objective: to alleviate or eliminate clinical symptoms and control the development of the disease.
Treatment principle: cat scratch disease patients with normal immunity tend to have a self-limiting course and generally do not need anti-infective drug treatment, with symptomatic treatment as the mainstay. For patients with low immunity, severe symptoms or atypical cat scratch disease, anti-infective treatment should be carried out as early as possible.
Symptomatic treatment
For those with skin lesions, wash and disinfect the affected skin, keep the affected skin clean, and apply gentamicin ointment if necessary.
Patients with fever should be cooled down, firstly by physical hypothermia, and if necessary, given ibuprofen and other antipyretic interventions.
Anti-infection treatment
For immunocompromised patients with severe symptoms or atypical cat scratch disease, anti-infective treatment should be given as early as possible.
Currently, commonly used drugs include gentamicin, rifampicin, azithromycin, ciprofloxacin and so on [9], which need to be selected under the guidance of doctors.
Surgical treatment
Surgical resection of the involved lymph nodes may be considered when repeated multiple pus extraction is ineffective, when a sinus tract with continuous drainage is formed, or when persistent pain interferes with normal life.
Prognosis
Cure
Cat-scratch disease is mostly self-limiting, and patients with normal immunity usually recover spontaneously with a good prognosis.
It can be cured after anti-infection treatment. Once the infection is cleared, most of the symptoms disappear and usually leave no sequelae. The mortality rate is low, less than 1%.
After being sick for once, it can obtain lifelong immunity.
Hazard
Central cat scratch disease can involve the cerebral nerves and spinal nerves, and those with unsatisfactory disease control can leave behind damage to the central nervous system, causing different degrees of sensory dysfunction and motor dysfunction, such as hypesthesia and muscle weakness.
A small number of patients with ophthalmopathic cat scratch disease may be left with different degrees of visual impairment, causing vision loss.
Daily
Daily management
Choose light, easy-to-digest food in daily life and eat more food rich in vitamins and proteins, such as oranges and lean meat.
Keep the living room comfortable, quiet and sunny, and open windows regularly for ventilation.
Pay attention to the clean and dry skin of the lesion area.
Pay attention to rest and avoid exertion.
Prevention
Management of infectious sources
Cats are hosts of Hansenula polymorpha, so regular bathing and preventive treatment are necessary when keeping cats at home.
Cutting off the infectious pathway
Clean cats regularly to reduce flea and tick parasites, especially during the warm and humid seasons, and strengthen deworming interventions for fleas and ticks on their bodies, as well as properly dispose of their excreta.
Protection of susceptible groups
Children and adolescents under 18 years of age should be protected by personal protection and instructed not to play with or come into close contact with cats, especially those who have not been vaccinated [10].
When scratched or bitten by cats, clean the wound promptly and seek medical attention.