What are the other Names for this Condition? (Also known as/Synonyms)

• Leishmania causing Enlarged Lymph Nodes
• Leishmania Lymphadenopathy
• Lymph Node Enlargement due to Leishmania

What is Leishmania Lymphadenitis? (Definition/Background Information)

• Leishmania Lymphadenitis is a condition of benign enlarged lymph nodes due to infection by the protozoan organism Leishmania. It is a condition of the lymph node(s) and related organs that is characterized by the benign reactive proliferation of lymphocytes (type of white blood cells) within the nodes
• The condition may be localized to a single group of lymph nodes (called Unicentric Leishmania Lymphadenitis) or may involve many lymph nodes and organs containing lymphoid tissue (called Multicentric Leishmania Lymphadenitis)
• Leishmaniasis is a widespread, global disease that is caused by a variety of Leishmania organisms, transmitted through the bite of an infected female sandfly (insect). It may affect the skin, mucosal membranes, or the entire body
• Leishmania causing Enlarged Lymph Nodes (or Leishmania Lymphadenitis) is a very uncommon manifestation of the disease, where the disease is localized or confined to the lymph nodes, generally without the involvement of the skin, mucosa, or internal organs of the body
• The risk factors for leishmaniasis include living in or visiting tropical and subtropical regions, where leishmania is endemic. This includes outdoor camping, occupations involving forest work, research, adventure, etc.
• The signs and symptoms of Leishmania Lymphadenitis are commonly dependent upon the site of involvement. The condition involves the lymph nodes in the armpits and groin area, and frequently, the inside of the upper arm (just above the elbow)
• The main symptoms associated with Leishmania Lymphadenitis include skin ulcers, fever, and weight loss. Enlarged lymph nodes are a common feature of this disease and the diagnosis is usually made by a tissue biopsy, taken from the affected region
• A lack of early diagnosis and prompt treatment can lead to complications. A significant complication due to Leishmania Lymphadenitis includes chronic infection, which can be fatal in some individuals
• The treatment for Leishmania Lymphadenitis is through the administration of medications (antimicrobial therapy). The prognosis depends on the extent of the disease and the individual’s response to treatment

Who gets Leishmania Lymphadenitis? (Age and Sex Distribution)

• Leishmania Lymphadenitis can affect individuals of all ages
• Both men and women can be affected and no gender preference is noted
• It can affect all racial and ethnic groups; however, leishmaniasis infection is more common in the tropical and subtropical regions of the world

What are the Risk Factors for Leishmania Lymphadenitis? (Predisposing Factors)

The risk factors for Leishmania Lymphadenitis may include the following:

• Living in or visiting tropical and subtropical regions, where Leishmania is endemic (the tropical and subtropical regions and southern Europe)
• The following set of people may have a higher risk while visiting or staying in the endemic areas: Adventure travelers, eco-tourists, ornithologists, soldiers, peace corps volunteers, missionaries, forest workers, etc.
• Individuals, who perform various research in the region, during the night or at twilight
• Outdoor camping in endemic areas exposing oneself to the insect bites
• Individuals with weak immune system owing to factors, such as HIV infection or other diseases, are more likely to contract leishmaniasis

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Leishmania Lymphadenitis? (Etiology)

Leishmania Lymphadenitis is caused by the bite of sandflies; small flying insects (3-6 mm in size) that are smaller than mosquitoes and less noisy. The sandflies transmit Leishmania organisms, which are protozoan parasites, in blood, causing infection. The transmission risk is high from dawn to dusk when the sandflies are active.

More than 20 different species of Leishmania parasites have been identified and studied. Some of the types of Leishmania parasites include:

• Leishmania tropica (or L. tropica)
• L. major
• L. aethiopica
• L. infantum
• L. donovani
• L. mexicana
• L. amazonensis
• L. venezuelensis (L. V.)
• L. [V.] braziliensis
• L. [V.] guyanensis
• L. [V.] panamensis
• L. [V.] peruviana

Very rarely, transmission can also take place during the following events:

• Blood transfusion, when contaminated blood or blood products are involved
• Sharing of contaminated needles
• Infected pregnant women can transmit the parasite to their unborn child

What are the Signs and Symptoms of Leishmania Lymphadenitis?

The signs and symptoms of Leishmania Lymphadenitis may include:

• Enlarged lymph nodes (termed lymphadenitis or lymphadenopathy); the superficial enlarged lymph nodes, just beneath the skin, are easily seen or felt
• The common lymph nodes involved include:
  • Lymph nodes in the elbow region (epitrochlear area), involved in about 70% of the cases
  • Groin area (inguinal lymph nodes), in about 20% of the cases
  • Armpits (axillary lymph nodes), in about 15% of the cases
• In some cases, almost all the lymph nodes may appear swollen
• Weight loss
• Fever
• Skin ulcers
• Enlarged liver and enlarged spleen

If the infection occurs on the skin it is called cutaneous leishmaniasis. When it affects different organs, it is called visceral leishmaniasis. Many individuals may not have any signs and symptoms, and so this condition is also referred to as silent leishmaniasis.

How is Leishmania Lymphadenitis Diagnosed?

A diagnosis of Leishmania Lymphadenitis is performed by obtaining biopsy samples from the affected region and examining them under a microscope to detect the cancerous cells. Other methods to aid in the study-diagnosis may include:

• A thorough physical examination and a complete medical history, which is very important
• Blood tests that may include:
  • Tests to detect antibodies against the parasite
  • Complete blood cell count (CBC) blood test
  • Chemistry panel
  • HIV testing
• Tissue culture and blood cultures can help in arriving at a diagnosis, by excluding other infections causing similar signs and symptoms
• Radiological imaging may be performed to determine the extent of infection in the body including:
  • X-ray of the affected region
  • Ultrasound scan of the affected region
  • Computerized tomography (CT) scan of the affected region: It helps detect any enlarged lymph nodes or organs in the body

Since the condition involves the lymph nodes, biopsies of enlarged lymph nodes are taken and examined in a lab to determine if the cells are malignant or benign. Even though the condition is benign, enlarged lymph nodes seen may also be noted in more serious conditions such as a lymphoma. For this reason, tissue biopsy is essential for accurate diagnosis. The biopsy may be performed under general or local anesthesia.

• Tissue biopsy from the affected area:
  • A biopsy of the affected tissue is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, flow cytometric analysis and very rarely, electron microscopic studies, to assist in the diagnosis
• The lymph node biopsy may be performed through any of the following procedures:
  • Fine needle aspiration biopsy (FNAB): A device called a cannula is used to extract tissue or fluid from the lymph nodes
  • Lymph nodes core biopsy of the enlarged lymph node
  • Lymph nodes open biopsy of the enlarged lymph node
• Bone marrow aspiration and biopsy is performed and sent to a laboratory for a pathological examination, to determine if the bone marrow is involved. Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, histochemical stains, molecular testing, and very rarely electron microscopic studies.
• Flow cytometry to identify cells as they flow through an instrument, called a flow cytometer. Flow cytometry measures the number and percentage of cells in a blood sample, and cell characteristics such as size, shape, and the presence of biomarkers on the cell surface. This method helps to rule out presence of the a malignant lymphoma/leukemia
• Polymerase chain reaction (PCR): It is used to measure the presence of certain biomarkers in blood, tissue or bone marrow cells. The test is ultrasensitive and detects extremely low amounts of biomarkers remaining in blood and tissue. A PCR test can also help confirm the diagnosis is some individuals when other methods for diagnosis are unsuccessful
• Lumbar puncture to determine if the brain is involved. The cerebrospinal spinal fluid (CSF) may be collected by inserting a needle in the spine and subjected to microscopic, flow cytometric, PCR, and biochemical analysis, to diagnose central nervous system (CNS) involvement, if any

Note: Differential diagnoses, to eliminate other causes of enlarged lymph nodes, are often considered before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Leishmania Lymphadenitis?

In many cases, a complete recovery is possible without any complications being noted. In some individuals, the complications due to Leishmania Lymphadenitis includes:

• Prolonged signs and symptoms that can last for several months
• 5% of individuals infected can have severe infection, which may be life-threatening
• Chronic infection: Recurrence of the condition that may be fatal

How is Leishmania Lymphadenitis Treated?

The treatment for Leishmania Lymphadenitis may differ from one individual to another and is also based on the severity of the condition. Proper consultation with the infectious disease consultants and public health officers are generally recommended before treatment starts.

• The treatment measures include medications against Leishmania infection (antimicrobial treatment). The medications administered vary depending upon the type of Leishmania species causing the infection
• The healthcare provider will determine the best course of treatment depending on each individual’s specific circumstances. Also, follow-up care with regular screening and check-ups are important post-treatment

How can Leishmania Lymphadenitis be Prevented?

The preventive methods for Leishmania Lymphadenitis include taking adequate precaution from sandfly bites. There is currently no vaccination available against Leishmania infection. The following measures are useful in controlling transmission of the condition:

• Avoid or limit exposure to sandfly bites
• Wear protective clothing, such as long sleeves, long pants, and socks, to protect the skin from the insect bites; minimize exposed skin areas
• Use insect repellents containing DEET, permethrin, or deltamethrine; one’s clothing and bed can be suitably sprayed with the repellents
• Prevent entry of sandflies into homes by keeping the windows and doors suitably closed, using finely-meshed bed nets (that are tucked into the mattress) while sleeping
• Sandflies are more active during dusk or at night; knowing their pattern, one can take steps to minimize outdoor activities or take suitable preventive measures against the bites accordingly
• Local strategies (specific to each community or locality) and community development to eliminate leishmaniasis should be encouraged
• Individuals with weak immune systems should be aggressively treated to address any underlying health condition causing the immunocompromised

Regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory. Often several years of active vigilance are crucial and necessary.

What is the Prognosis of Leishmania Lymphadenitis? (Outcomes/Resolutions)

• The prognosis for Leishmania Lymphadenitis is generally excellent, with the majority of infected individuals recovering from the condition within a couple of weeks to a month
• However, the prognosis may depend upon a set of several factors, which include:
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Involvement of vital organs may complicate the condition
  • Whether the condition is occurring for the first time, or is a recurrent. Recurring episodes have worse prognosis compared to the condition that does not recur
  • Response to treatment: Individuals that respond to treatment have better prognosis compared to individuals that do not respond to treatment
  • Progression of the condition makes the outcome worse 
• Early diagnosis and appropriate treatment of the infection generally yields satisfactory outcomes, than a lack of treatment or inadequate treatment

Additional and Relevant Useful Information for Leishmania Lymphadenitis:

General information on lymph nodes:

The lymph nodes are part of one’s immune system. The lymph nodes are present throughout the body, usually in groups. In normal healthy adults, one cannot feel (see or touch) the lymph nodes readily. However, if they are enlarged, they can be felt either by the individual himself/herself or by the healthcare provider.

Enlarged lymph nodes can occur in both benign and malignant conditions. Hence, the cause of enlarged lymph nodes should be evaluated. If no obvious cause for enlargement of lymph nodes is found, then the possibility of a lymph node malignancy should be ruled out.

In a majority of individuals, a lymph node swelling is caused by a benign process such as an inflammation or infection. In many cases, swollen lymph nodes are part of other signs and symptoms. This can help a healthcare provider arrive at a list of follow-up tests and ensure an accurate diagnosis. Superficial enlarged lymph nodes can be felt by the healthcare provider through palpation. Enlarged lymph nodes deep in the body are often detected by radiological studies such as X-rays, ultrasound scan, CT and MRI scans.

Some enlarged lymph nodes can be painful, while others may be painless. Depending upon the underlying cause, enlarged lymph nodes can be localized to a particular area of the body, or they can be generalized, meaning that they are present throughout the body.