Histiocytic necrotizing lymphadenitis is an inflammation of the lymph nodes in the neck that may be accompanied by general symptoms such as fever or vomiting. Affected individuals are usually Asian women in early adulthood whose blood titers to Yersinia enterocolitica are elevated. Little research has been done on the disease, so only therapeutics are available for symptomatic treatment.
What is histiocytic necrotizing lymphadenitis?
Lymphatic fluid plays a critical role in the human immune system and is transported through tissues along lymphatic pathways. In lymphadenitis, the lymph nodes are inflamed, so usually in the setting of an acute or chronic persistent infection. Lymphadenitis is a variant of lymphadenopathy and can occur in different forms. Histiocytic necrotizing lymphadenitis is a variant of lymphadenitis characterized by necrosis without granulocyte inclusions. The disease is also known as Kikuchi syndrome and occurs primarily in Asia. Cases have also been reported in Europe, but Europeans are much less commonly affected compared to Asians. The disease mainly affects women. Figures show that the female population is even three times more likely to suffer from histiocytic necrotizing lymphadenitis than men. In most cases, the disease occurs in young adults and lasts an average of two months.
Causes
Little is known to date about the exact cause of histiocytic necrotizing lymphadenitis. Many scientists invoke a putative association with an elevated blood titer against Yersinia enterocolitica, as has been observed in a large proportion of patients to date. If such a causal relationship exists, it is possible to speak of an infectious genesis. The previous cases of disease often occurred as a result of infections. This association may also play a role in the pathogenesis of the disease. Some researchers reject the purely infectious genesis and consider histiocytic necrotizing lymphadenitis to be an autoimmunological reaction of the body. Whether the disease could be an infection-independent immune disorder has not yet been further clarified. The extent to which the Asian background plays a role in the pathogenesis is equally uncertain.
Symptoms, complaints, and signs
In most cases, histiocytic necrotizing lymphadenitis affects the lymph nodes in the neck region. Some patients suffer from pathologic changes on only one side. Others suffer from bilateral inflammation. In almost no cases has the inflammation spread to other lymph nodes. The inflamed tissues swell up to three centimeters, but usually do not cause any pain. As a rule, the inflammation is accompanied by general complaints. Those affected often feel similar to an infection. The most common general complaints are fever, fatigue, tiredness, headache and dizziness. These symptoms may be joined in individual cases by other accompanying symptoms similar to the common cold. Vomiting and sore throat are conceivable. However, absolute lack of symptoms is also conceivable. Some patients hardly notice the disease for this reason. In the case of subjectively perceived lack of discomfort, for example, the swelling of the lymph nodes may not be noticed until a routine examination.
Diagnosis and course of the disease
The diagnosis of histiocytic necrotizing lymphadenitis is investigated by history, palpation, sonography, and histology, if necessary. Macroscopically, there is induration of the lymph nodes in the neck, whereas all other lymph nodes are unremarkable. Histology reveals a widened T-zone or paracortical zone with smaller necrotizing foci. Characteristically, plasmacytoid monocytes are found in the zone. The foci are again mostly populated by histiocytes. Granulocytes are completely absent. To confirm the diagnosis, the physician must necessarily resort to a tissue sample in the sense of taking a lymph node. All other procedures do not allow a definite diagnosis and can only indicate that pathological changes are present. The prognosis for patients with histiocytic necrotizing lymphadenitis is rather favorable despite the below-average research situation.Most patients are cured without remission. Only a few of those affected develop sequelae such as SLE.
Complications
In general, this disease mainly causes discomfort in the neck and lymph nodes. However, the symptoms usually spread to only one side of the body. Relatively severe swelling and pain occur in the affected areas. If the pain occurs in the form of pain at rest, it can thus also lead to sleep problems for the patient. There is often a general feeling of illness and fatigue. The ability of the affected person to cope with stress decreases and it is not uncommon for fever and fatigue to occur. Furthermore, most of those affected suffer from nausea and vomiting and complain of severe headaches. The quality of life is considerably limited and reduced by this disease. In many cases, patients no longer actively participate in life and withdraw. Furthermore, loss of consciousness may also occur, which may be associated with a fall. A causal treatment of this disease is not possible, which is why only the symptoms can be limited. Medications are used and there are usually no complications. In most cases, the symptoms disappear after about a month and do not reappear thereafter. Life expectancy is usually not reduced.
When should you see a doctor?
Histiocytic necrotizing lymphadenitis primarily affects Asian women in young adulthood. Individuals in this high-risk group should see a doctor as soon as they experience vomiting or fever. If the symptoms persist for several days or weeks, it is advisable to have a check-up. If the lymph nodes are swollen on one side, if the throat is sore, if it is difficult to swallow or if pain occurs when the throat is touched, a doctor should be consulted. If there is fatigue, headache, malaise or dizziness, a medical examination should be done. The flu-like symptoms increase in intensity in histiocytic necrotizing lymphadenitis if there is no treatment; moreover, the condition then persists for several months. This affects the performance of daily duties and may lead to further complications. Fatigue, internal weakness and a general feeling of illness should be investigated if there is no improvement within a few days. Sleep disturbances, as well as decreased performance, need to be investigated. In case of stress, psychological problems, mood swings or behavioral problems, a doctor should be consulted. People who do not belong to the risk group but nevertheless suffer from the described complaints are also advised to see a doctor.
Treatment and therapy
The causes of HNL have not yet been conclusively determined. Therefore, no causal treatment option is available for patients with the disease to date. For this reason, purely symptomatic treatment is indicated, primarily to improve the subjectively experienced symptoms. In most cases, symptomatic treatment consists of administration of analgesics and antipyretics or non-steroidal anti-inflammatory drugs. Other conservative drug treatment options include corticosteroids. However, these medications are rarely necessary for sufferers, as medications with far fewer risks and side effects already lead to improvement in most patients. Spontaneous improvement often occurs after one month with the administration of analgesics or antipyretics. However, cases are also known in which the symptoms did not subside until after four months. Whether the drugs are actually responsible for the spontaneous improvement or whether the remission in all documented cases was due to endogenous processes remains controversial. Because histiocytic necrotizing lymphadenitis may develop into SLE, according to the documentation to date, patients are advised to have regular follow-up for the next several years of life.
Outlook and Prognosis
Histiocytic necrotizing lymphadenitis usually has a good prognosis. In most cases, a self-limiting course occurs. Thus, the disease heals on its own. Not much is known about the cause of the disease. Typical is the occurrence of lymph node swelling after infections.Since the disease occurs mainly in Asia, it must be a more common infection there. The bacterium Yersinia enterocolitica is suspected of triggering an autoimmunological process leading to histiocytic necrotizing lymphadenitis. It usually affects young women. The disease is observed much less frequently in men. Histiocytic necrotizing lymphadenitis is often not diagnosed because it is very rare and its symptoms resemble many other often more serious diseases such as adenocarcinoma, malignant lymphoma or systemic lupus erythematosus (SLE). However, the correct diagnosis also enables the correct therapy. In the case of histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto lymphadenitis), this is limited to symptomatic measures. A causal therapy is not yet possible due to the low level of knowledge. However, it is also not necessary, because the disease usually heals on its own. Spontaneous improvement occurs after one to four months. However, monitoring of patients for several years is recommended because the development of systemic lupus erythematosus cannot be ruled out.
Prevention
The cause of histiocytic necrotizing lymphadenitis is not yet known in detail. Until science will have settled on a cause, no promising preventive measures for the disease will be available. If an infectious cause can indeed be assumed, general infection prophylaxis may be considered as a prevention option.
Follow-up
Therapy for histiocytic necrotizing lymphadenitis transitions directly to follow-up. Patients can take an active role in interventions to promote healing. This is related to the symptomatic approach to disease treatment. It is important that those affected undergo regular check-ups, keeping a close eye on their symptoms. In this way, physical weaknesses can be identified and combated in good time. Medical care and support with individually tailored medications improve the quality of life. This not only helps against the symptoms of the disease, but also promotes social contacts. Follow-up care also includes proper nutrition, which strengthens the immune system with plenty of vitamins and nutrients. As a result, those affected feel more vital and take a more relaxed approach to their illness. In addition to reduced stress, it is very important that patients are aware of their bodies. In this way, any complications triggered by the medication can be detected at an early stage. If side effects become apparent, a short-term appointment with a specialist is necessary. This helps patients to check their symptoms and, if necessary, readjust their medication. Thus, close contact between patient and physician is beneficial for follow-up care.
What you can do yourself
In the therapy of histiocytic necrotizing lymphadenitis, the active participation of the patient in cooperation with the treating physicians is of great importance. This is because a causal therapy of the disease is not yet possible, so that only symptomatic treatment approaches are practicable. In this context, patients provide decisive information about the respective complaints, so that appropriate medications can be applied. Many patients suffer from general symptoms of the disease such as fever and fatigue. In severe cases, the physical fatigue leads to social withdrawal and difficulties in performing one’s job. In this case, medical care is particularly important in order to prescribe appropriate medication for the patient or to positively influence the body’s defenses and subjective body image by changing the patient’s diet. A diet rich in vitamins and nutrients supports the immune system of individuals with histiocytic necrotizing lymphadenitis. Thus, at best, patients gain a sense of increased vitality and experience the time during treatment as less stressful. Because multiple medications are sometimes needed for different symptoms, patients pay attention to possible complications and side effects of the medications. If the symptoms are unclear, the sufferers contact the specialist or an emergency physician.
