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Sclerotic erythema (Latin erythema induratum) is a skin condition associated with tuberculosis infection. Check what is characterized by sclerotic erythema, what are its symptoms, what is the diagnosis and treatment of sclerotic erythema.

Sclerotic erythema(Latinerythema induratum ) is a skin disease associated with tuberculosis infection. Although the incidence of tuberculosis continues to decline in developed countries, it is worth knowing how many forms this infectious disease can take. It is currently believed that sclerotic erythema is not a symptom of direct tuberculosis involvement of the skin, but an expression of the organism's hypersensitivity to the presence of tuberculosis mycobacteria.

Sclerotic erythema - example of tuberculide

According to statistics, in about 1% of tuberculosis patients the disease takes the skin form. We divide skin tuberculosis into two categories: dermal tuberculosis and tuberculides. Dermal tuberculosis is the direct involvement of the skin by mycobacteria.

Tuberculides are considered to be a group of skin diseases associated with tuberculosis infection, but not due to the presence of tuberculosis in the skin. Sclerotic erythema is an example of just such a tuberculide. The reason for its development is the hypersensitivity of the organism to antigens of mycobacteria.

When we take a slice of skin affected by indurated erythema and examine it microscopically, we will not find tuberculosis-causing bacteria in it. However, other characteristic features will be present: inflammation in the subcutaneous tissue and involvement of small blood vessels.

All these changes are taken as an expression of an overactive immune system caused by the presence (at the time of symptoms or in the past) of mycobacteria elsewhere in the body.

Sclerotic erythema not related to tuberculosis

So far we have focused only on erythema indurated as a disease related to the organism's hypersensitivity to tuberculosis. At this point, however, it is worth mentioning that this correlation does not apply to all cases of indurated erythema.

It is true that many patients have a confirmed association of skin lesions with tuberculosis, but there are also those in whom sclerotic erythema appears in othercircumstances.

The mechanism of development of skin lesions is analogous to the form associated with tuberculosis, but the hypersensitivity of the immune system is caused by another etiological factor (such as antigens of other microorganisms).

Sclerotic erythema - symptoms

Since we already know what causes sclerotic erythema, let's move on to the description of the typical features of this disease. Sclerotic erythema is characterized by the presence of skin lesions in the form of multiple, hard tumors that can cause severe pain.

The ongoing inflammatory process involves the deep layers of the skin as well as the subcutaneous tissue. The surface of nodular lesions becomes dark red in color.

Sclerotic erythema is more often diagnosed in women than in men. The disease "eagerly" affects the lower limbs, especially the calves. Its course is chronic and often recurrent - after some changes heal, new ones may appear.

Sclerotic erythema - characters

Due to the appearance of skin lesions and the course of the healing process, there are two forms of indurated erythema:

  • erythema sclerosis - ulcerative form

Ulcerative sclerotic erythema is a variant of the disease with a relatively more severe course. In this form, ulcers appear in the central parts of the tumors, which are long and difficult to heal.

In such a state, it is also easier to superinfect them, which additionally hinders the healing process. Even after the changes have subsided, the skin may be left with permanent marks in the form of discoloration and scars.

  • erythema sclerosis - non-ulcerative form

The non-ulcerative form of indurated erythema is slightly milder. Skin changes heal more easily. Subcutaneous tumors are absorbed without leaving any permanent traces.

Sclerosing erythema - diagnosis, diagnosis

The diagnosis of sclerosing erythema requires several types of tests; the disease is diagnosed on the basis of a thorough physical examination, microscopic examination of a section of the affected skin, as well as additional tests for tuberculosis.

The typical clinical features of sclerotic erythema are localization within the shins, the characteristic appearance of nodular lesions, and a chronic, recurrent course. Such symptoms are usually an indication for a skin biopsy to be taken and for further examination.

First of all, such a fragment is viewed under a microscope. Sclerosing erythema is characterized by the presence of microvasculitis, as well as an inflammatory infiltrate in the subcutaneous tissue. They are nothowever, pathognomic changes for this disease - this means that a direct diagnosis cannot be made on their basis. Such a microscopic image may also accompany other diseases.

The next step in the analysis of the material obtained during the biopsy is microbiological testing. Their goal is to look for infectious agents - bacteria, viruses or fungi that cause clinical symptoms. In the case of indurated erythema, no positive result of such an examination should be expected.

We will not find tuberculosis mycobacteria in the skin sample. As mentioned earlier, sclerotic erythema is not a type of dermal tuberculosis - it is only an expression of the organism's hypersensitivity to the presence of mycobacteria in a different location.

The latest methods of molecular diagnostics, including the PCR method, allow to find the minimum amount of bacterial DNA within skin lesions. The use of the PCR method gives a greater chance of finding traces of the presence of mycobacteria in the skin, although in the case of indurated erythema it is also not a rule. A negative result of the PCR test does not exclude the possibility of diagnosing this disease.

Suspicion of indurated erythema is always an indication to perform the so-called tuberculin test. It is a test of the reactivity of the immune system to Mycobacterium tuberculosis.

The tuberculin test involves the intradermal injection of mycobacterial antigens (so-called tuberculin), and then observing how the subject's body reacts to them. After 72 hours, a measurement of the allergic reaction is made around the injection site.

Since sclerotic erythema is a symptom of hypersensitivity of the organism to antigens of Mycobacterium tuberculosis, the tuberculin test for this condition gives a strongly positive result (large diameter allergic reaction).

The presence of erythema sclerosing skin lesions usually requires additional tests to find hidden tuberculosis spots. For this purpose, among others, imaging examinations of the lungs (chest X-ray) are performed.

As you can see, the diagnosis of sclerosing erythema requires many types of tests. Unfortunately, even following the guidelines does not always allow for obtaining results that will confirm the diagnosis in 100%.

In such a situation, an attempt is usually made to implement standard anti-tuberculosis therapy. If the skin changes disappear after its application, it is also a proof of the correctness of the diagnosis.

Sclerotic erythema - treatment

Treatment of erythema sclerosis involves the use of anti-tuberculosis drugs.Anti-tuberculosis therapy is a multi-drug and long-term therapy.

The treatment regimen is selected individually for each patient. Typically, an intensive treatment for tuberculosis is initially implemented, with (for example) a combination of rifamipicin + isoniazid + pyrazinamide + ethambutol.

After two months of such treatment, the patient switches to the so-called maintenance treatment, the task of which is to maintain the current treatment effects and to neutralize mycobacteria that could survive the first phase of treatment.

Maintenance therapy usually takes another four months. It uses isoniazid (often in combination with rifampicin).

Additional pharmacological agents used to treat erythema sclerosis, such as non-steroidal anti-inflammatory drugs (ibuprofen), relieve pain in difficult-to-heal skin lesions.


Tuberculosis - basic information about the disease

Tuberculosis is an infectious disease caused by bacteria called Mycobacterium tuberculosis (LatinMycobacterium tuberculosis ). Tuberculosis often affects the lungs first, although this is not always the case.

There are many varieties of tuberculosis - there is actually no organ that cannot be infected by mycobacteria. Therefore, we distinguish

  • pulmonary tuberculosis
  • renal tuberculosis
  • tuberculosis of the central nervous system
  • tuberculosis of the urinary system
  • gastrointestinal tuberculosis

Mycobacteria are a special type of bacteria. One of their characteristic features is the multiplication of macrophages inside the cells of the human body.

Mycobacteria like to live inside macrophages and can travel with them throughout the body. In this way, they colonize various organs in which they can stay hidden even for several years. We are talking then about latent tuberculosis - the mycobacteria are present inside the body, but they do not cause any clinical symptoms.

Such a wide variety of forms of tuberculosis means that it is considered an extremely insidious disease.

About the authorKrzysztof BialaziteA medical student at Collegium Medicum in Krakow, slowly entering the world of constant challenges of the doctor's work. She is particularly interested in gynecology and obstetrics, paediatrics and lifestyle medicine. A lover of foreign languages, travel and mountain hiking.

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