erythema nodosum

Erythema nodosum is a disease that affects the skin and subcutaneous tissue, most often on the legs. The patient has bumps and nodes of red color on the skin, the skin becomes uneven. In addition to an unattractive appearance, erythema nodosum causes a lot of inconvenience to its “owner”, since the resulting bumps hurt from touch and pressure. The very process of formation of manifestations of the disease is usually associated with the presence of other pathologies, but sometimes it can be an independent disease. In any case, the presence of erythema in a person requires qualified medical intervention.

According to ICD 11 (International Classification of Diseases 2021), the disease has been assigned the code L52.

Erythema nodosum: what it is, how it manifests itself

Erythema nodosum is an inflammatory disease locally affecting the subcutaneous and cutaneous blood vessels. The impetus for its development is an allergic reaction, and erythema itself is a type of allergic vasculitis. On the affected area, characteristic spherical or hemispherical nodes of various sizes appear. Most often, these nodes appear on symmetrical areas of the lower extremities, although sometimes they affect the face and hands.

The disease can develop in a person of any gender and age, but is mainly diagnosed in women aged 20-30 years. For 4-6 sick women, there is only one man with such a pathology. It is believed that in winter and spring the incidence increases slightly. Erythema nodosum occurs in about 30-40% of humanity, so it can be called a common disease.

For the first time the name of the pathology was proposed at the beginning of the 19th century by the British dermatologist Robert Willan. Her allergic nature was discovered much later, and before that it was believed that erythema nodosum is an independent specific nosological unit.

Unlike systemic vasculitis, erythema is localized and limited and does not spread throughout the body.

The appearance of the affected area becomes bumpy, which is due to the somewhat loose, uneven surface of the skin with tubercles.

Causes and mechanism of development of erythema nodosum

There are several types of erythema, depending on the etiology of the process. An independent disease is called primary erythema, but if the problem appeared against the background of other pathologies, mainly of a chronic, background nature, it is called secondary.

The etiology of the primary type of the disease, to date, has not been fully studied. According to most scientists, the occurrence of this type of erythema should be associated with a genetic predisposition. Most often, the disease manifests itself as a nonspecific immunoinflammatory syndrome.

It can be caused by two types of reasons:

• infectious;
• non-infectious.

So, infectious risk factors for the development of erythema nodosum:

• streptococcal and staphylococcal infections, including tonsillitis, scarlet fever, erysipelas, rheumatoid arthritis, cystitis;
• tuberculosis;
• chlamydia;
• histoplasmosis;
• some herpes viruses: Epstein-Barr, cytomegalovirus;
• psittacosis;
• yersiniosis;
• trichophytosis;
• syphilis and gonorrhea;
• toxoplasmosis, and some others.

Non-infectious causes of the disease:

• sarcoidosis (most common in patients with non-infectious erythema);
• leukemia;
• Behcet’s syndrome;
• vaccination against certain infectious diseases;
• inflammatory processes in the intestines, for example, ulcerative colitis and Crohn’s disease;
• tumors and neoplasms of a different nature;
• lymphogranulomatosis;
• taking certain drugs, for example, sulfonamides, iodides, salicylates, a number of antibiotics, hormonal oral contraceptives.

In women, erythema nodosum may develop during pregnancy.

How does pathology develop? The disease is a reactive process, with the involvement of organs and systems in it – this is evidenced by a wide variety of antigenic stimuli that cause the development of erythema. Like the etiology, the pathogenesis of erythema nodosum is not fully understood, but doctors suggest that it is based on immunocomplex hypersensitivity reactions associated with the formation of immune complexes. These complexes are deposited around the venules of the connective tissue septa in the subcutaneous fat layer. There is also a delayed reaction. The immune response characteristic of the secondary type of disease develops due to the pathology of the organ or organs that has developed within the framework of the primary disease. For example, in a patient with sarcoidosis, a Th-1 type 9 immune response occurs, and CD4+ T-lymphocytes accumulate. In addition, the defeat of sarcoidosis is accompanied by a high level of activity of lymphocytes and macrophages at the site of the pathology. These cells, for unknown reasons, accumulate in a particular organ, provoking an increase in the number of interleukins of several types, as well as tumor necrosis factor alpha. It is TNF-alpha that is referred to as the main cytokines involved in the formation of sarcoidosis granuloma.

The most common pathogenic element that provokes the appearance of erythema nodosum is the causative agent Chlamydophila pneumoniae. The microorganism has a high tropism for the vascular endothelium. After chlamydia enters the bloodstream, it multiplies for a long time and accumulates in vascular cells, macrophages, monocytes and altered tissues.

Usually, manifestations of erythema nodosum occur on the lower extremities, on the legs, on the inside of the thighs, but can be found on the face, buttocks, forearms, and abdomen. Why the disease is predominantly located in the area of ​​​​the legs, doctors are still unknown. It is believed that this part of the leg has a relatively weak level of arterial blood supply in combination with a weakened venous outflow due to a pronounced gravitational effect, as well as insufficiency of the muscle pump.

The course and main symptoms of the disease

If we consider the pathology by the nature of its course, and by the degree of prescription of the inflammatory process, there are several forms of its course:

• acute;
• subacute, or migratory;
• chronic.

In the first case, the disease has a pronounced acute onset. Bright red painful knots quickly form on the legs, the tissues around which become swollen. The condition is accompanied by a rise in body temperature to 38-39 degrees, headache, weakness. Before the patient begins to form nodes, he may have a viral infection, streptococcal pharyngitis, or tonsillitis. With such a course, after 5-7 days, the nodes disappear without a trace, leaving no wounds and ulcers. The chance of recurrence is very low. Negative consequences, in most cases, are not formed, and the disease passes without complications.

With a migratory course, the clinical manifestations are similar to the acute form, but the inflammatory component is less pronounced in humans. In addition to the general picture, small nodules of a single nature, often of an asymmetric arrangement, may appear. There is a peripheral increase and growth of nodes, their resolution in the center zone. If the disease does not go away within 2-3 months, it is likely that it occurs in a migratory form.

A relapsing course is usually observed in women in middle and old age, especially if the patient has allergic reactions, vascular pathologies, inflammatory and infectious processes, tumor diseases. Exacerbations occur in the spring and autumn months. The nodes appear on the anterior-posterior parts of the lower leg, reach the size of a walnut, they are painful on palpation and are accompanied by swelling of the legs and feet. A relapse can last up to several months, and against the background of the resorption of older nodes, new ones form at this time.

The development of the initial, quite characteristic symptoms of nodular erythema may be preceded by a prodromal period – it lasts from 1 to 3 weeks, proceeds in the form of a febrile state, in which arthralgia and increased fatigue are observed.

First, a rash appears – sharply and suddenly. An acute appearance is accompanied by a rise in temperature up to 39 degrees, coughing, a feeling of nausea, followed by vomiting, headache and abdominal pain, loosening of the stool. Localization of the rash – on the legs, in the area of ​​​​the ankles and knee joints. If rashes appear on the thighs, on the face, neck, on the hands, then erythema has a general distribution.

The rash is soft and warm to the touch nodes that can reach up to 5 centimeters in diameter with a severe form of the current. At first, they have a bright red color, rise slightly above the skin, which is why it takes on a bumpy appearance, as if boils are forming on it. After a few days, the bumps become flat, their color changes to a purple-red or crimson-red hue. Further, the site of the node becomes like a deep bruise with a yellowish or greenish color. It is this change in the color of the affected area that allows for differential diagnosis in the later stages of the development of the disease.

Due to the fact that the tissues around the nodes acquire severe swelling, it is quite difficult to establish clear boundaries of the node, but there is pain on palpation, as well as a spontaneously appearing pain syndrome.

Each of the nodes exists for about a week, sometimes up to two weeks, after which it begins to slowly disappear. At the same time, the tissues do not undergo the development of atrophy, they do not form scars. The appearance of ulcers for sites of healing of nodes is also not typical.

If we are talking about a subacute or recurrent type of the disease, new nodes form within 3-6 weeks, sometimes longer. Some nodes may “live” for several months, and be observed along with more recent rashes.

Associated manifestations:

• subfebrile temperature;
• general weakness and malaise;
• appetite disorders;
• myalgia.

In 50% of cases, arthralgia and arthritis are present, while large joints are most often affected – the ankle, wrist and knee. The development of deformations is not observed.

In children, the disease progresses faster, fever is observed in less than half of young patients.

Diagnosis and treatment of erythema nodosum

The diagnostic process, first of all, includes a patient interview and an external examination. The doctor needs to clarify the presence of chronic, concomitant diseases, against which erythema could develop, since the treatment of the condition can be effective only if it affects the root cause of its appearance.

In addition to passing various tests, for example, general blood and urine, PCR tests for various viruses, an analysis to determine the titer of antistreptolysin-O, the patient may be prescribed an x-ray or CT scan of the chest to determine the presence of enlarged lymph nodes, symptoms of tuberculosis or Lofgren’s syndrome. With a severe form of the disease and the ineffectiveness of therapy, the patient may be referred for a biopsy of the affected tissues, followed by a histological analysis.

Indicators of the general blood test provide only superficial information: in the acute period or exacerbation of the chronic course, the patient has an increase in ESR and neutrophilic leukocytosis.

Analysis of a nasopharyngeal swab for culture often shows the presence of a streptococcal infection. Stool culture is performed to confirm the presence of yersiniosis. Patients with severe articular syndrome are referred for a blood test for rheumatoid factor.

To make a diagnosis and identify the etiology of the problem, the patient sometimes has to visit more than one doctor – a pulmonologist, an infectious disease specialist, a vascular surgeon, an otolaryngologist, and also undergo various specific examinations (pharyngoscopy, rhinoscopy, rheovasography of the lower extremities, ultrasound of the veins of the extremities).

Difficulty may arise at the stage of differentiation of erythema nodosum with an indurative form, with skin tuberculosis, migratory thrombophlebitis, syphilitic gums, and nodular vasculitis.

A pronounced picture of the clinic of the disease requires adherence to bed rest for 7-10 days – this measure allows you to reduce the load on the lower extremities, somewhat reduce swelling and pain. The legs are laid a little higher than the head, pillows are placed under them. For severe cases, the use of elastic bandages and special compression stockings is allowed.

Recommendations for drug treatment include the use of non-steroidal anti-inflammatory drugs – Ibuprofen, Indomethacin, Paracetamol, Ortofen, Nimesil. Such drugs are relevant for mild and moderate forms of the course. The course of admission is 3-4 weeks.

In the case of a bacterial or viral infection, the patient is prescribed antibacterial drugs, antibiotics, and virusostatic drugs. Pregnant women, especially during the first trimester, are prescribed antibiotics of the penicillin group, cephalosporins, macrolides, as they are the safest for the unborn child – it can be Oxacillin, Ceftriaxone, Cefoxitin, Azithromycin. Although, if possible, it is better not to take them until the second trimester.

Anti-inflammatory drugs with antimicrobial, analgesic and antiplatelet properties, such as Delagil or Plaquenil, are also undesirable for pregnant women, but other groups of patients can be defined as the main drug therapy.

To improve microcirculation, reduce thrombosis and swelling, patients are prescribed iodine-containing agents, as well as iodine substitutes that suppress hypersensitivity reactions.

Patients with allergic reactions are prescribed antihistamines (Loratadine, Fexofenadine). Vitamins of group B, vitamin A and E are used as an injection for general strengthening of the body. If the patient is not allergic, it is also advisable to prescribe a course of vitamin C.

In severe cases of the disease, treatment in adults may include the use of Heparin or Fraxiparin. Angioprotectors help to increase vascular tone, reduce swelling and permeability of the vascular walls, improve the rheological characteristics of the blood, so patients are prescribed Curantil, Vasonit, Pentoxifylline.

Erythema nodosum with a prolonged course, when there is an intense inflammatory process, and the previously prescribed treatment does not give results, requires the appointment of glucocorticosteroid drugs – Metipred, Dexamethasone. In small concentrations, they are prescribed even for pregnant women.

For patients with the most complex and persistent course of the disease, hemosorption and plasmapheresis procedures are necessary.

Local treatment consists in the use of applications and compresses with a solution of Dimexide, Ichthyol. You can use Dimexide gels mixed with Heparin, as well as cream with indovazin, ointments and creams with corticosteroids – Beloderm, Belogent, Belosalik.

Physiotherapeutic procedures such as applications of ozokerite, phonophoresis with dibunol liquid liniment, with heparin, with lidase and hydrocortisone, can be used only after acute inflammatory manifestations have been stopped. Among other effective procedures for erythema nodosum are magnetotherapy, inductothermy, and the use of a laser.

Taking antibiotics, as the main direction of treatment, should be prescribed carefully, since their increased use can contribute to the transition of the acute stage of the disease to the chronic one.

In general, the treatment regimen is usually based on reducing the degree of local inflammation, and does not have a generalized direction.

Erythema nodosum is a disease associated with inflammation of the tissues of the subcutaneous fatty tissue. Initially, it is formed against the background of allergic processes, and the factors contributing to the development are bacterial and infectious diseases, pregnancy, leukemia and sarcoidosis, tumor processes in the body.

The prognosis for an adequately designed treatment regimen is favorable – usually after 3-4 weeks a person feels healthy and can return to his usual way of life.

However, in rare cases, the disease becomes severe, turns into chronic inflammation, with a long severe course. Such patients, in addition to traditional and qualified drug therapy, use various folk remedies, for example, ichthyol ointment, infusion of horse chestnut leaves, garlic with honey, a mixture of aloe leaves, honey and lemon juice.

To reduce the likelihood of pathology, doctors recommend eating currants, green tea, citrus fruits, chicken meat, vegetable oil, eggs, liver, milk, more cabbage, pumpkin, eggplant, tomatoes, garlic and onions, oily fish, cherries, dill, as these products bring a significant amount of vitamins C, PP, E into the diet, and some contribute to blood thinning. It is especially important to strengthen the immune system in difficult autumn and winter times.

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