Erythema nodosum is a rheumatic disease that affects the skin and is characterized by red nodules on the extensor sides of the lower legs, rarely occurring on the thighs and forearms.
It is a type of panniculitis, an inflammation of the subcutaneous fatty tissue.
The erythema nodosum can pass on its own within three to six weeks.
After subsiding, it can leave:
- a temporary livid appearance,
- a permanent recess in the skin where the fat layer was affected.
Chronic erythema nodosum is a condition in which the lesions can form anywhere for a few weeks or months.
Nevertheless, this disease persists for years.
Erythema nodosum with chronic intermittent flare-ups can occur with or without an underlying disease.
Who is affected by erythema nodosum?
Most cases of erythema nodosum occur between the ages of 20 and 45, with a peak between the ages of 20 and 30.
Rarely, elderly people or children are affected.
The frequency in adult women is 3 to 6 times greater than in adult men.
Before puberty, gender does not matter.
Most people with erythema nodosum had before the onset of the disease:
- an acute infection,
- a disease.
What are the causes of erythema nodosum?
Erythema nodosum appears to be a hypersensitivity reaction (of the immune system) with various causes.
The most common causes of erythema nodosum are:
- strep throat; this may be caused by streptococci or a virus.
- Sarcoidosis; in sarcoidosis, erythema nodosum is often associated with enlarged lymph nodes (hilus lymph nodes) in the chest.
This phenomenon is known as Löfgren’s syndrome.
It is a variant of sarcoidosis that can cause:
- Tuberculosis (TB): erythema nodosum can present as a primary infection in TB.
Tuberculosis can also cause erythema induratum (Bazin’s disease), characterized by rashes that can ulcerate and are located in the calf area.
- birth control pill; erythema nodosum can occur after the first 2 or 3 cycles of birth control pills.
- pregnancy; erythema nodosum can occur in pregnant women, but then passes again after the birth of the child.
It may recur with another pregnancy.
- Other medications; some drugs can cause erythema nodosum, among these are:
- anti-inflammatory drugs (NSAIDs) such as aspirin,
- gold salts,
- Antibiotics: penicillin, amoxicillin, minocycline.
- Inflammatory bowel disease (ulcerative colitis or Crohn’s disease).
- Behçet’s disease, which also causes:
- Aphthae in the mouth,
- arthritis, especially of the knees and wrists,
- some eye diseases (uveitis and conjunctivitis).
- Some tumors, including:
- Escherichia coli
- Sexually transmitted diseases: gonorrhea, syphilis, chlamydiosis, venereal granuloma
- Mycoplasma pneumoniae
- Pseudomonas aeruginosa
- Dermatophytosis (tinea corporis)
Infections caused by protozoa:
- by roundworms (Ascaris)
- Idiopathic diseases, because sometimes the cause is unknown.
What are the symptoms of erythema nodosum?
1. Before the nodules appear, a general feeling of sickness occurs a few weeks before.
2. The following shall be observed:
- enlarged lymph nodes in the chest area.
You can also lose weight during this time.
3. Patients also report:
- Joint pain
- general discomfort in the lower extremities.
4. Joints may swell.
Ankle joints, knees and wrists are commonly affected, other joints involved include:
5. The pain in the legs and joints may persist for a few weeks or months after the nodules appear.
The nodules that occur in erythema nodosum can reach a size of 1 to 10 cm.
The edges of the nodules are not well defined.
The shins are the most common localization. Other frequently affected areas are:
The nodules appear all over the body.
Each nodule persists for about two weeks, but new nodules can form within six weeks.
To begin with, the nodules are:
As a result, they become softer.
When a nodule passes, it becomes bluish-livid, and later yellowish.
It usually takes a few weeks for the nodules to completely pass. The symptoms can persist for months, after which they disappear completely.
No scars remain.
Sometimes only two, other times up to 50 nodules can form.
Symptoms of erythema nodosum depending on the causative disease
For example, the nodules of erythema nodosum may appear two to three weeks after a streptococcal infection of the throat.
People with inflammatory bowel disease may suffer from:
In people suffering from chronic bowel diseases, erythema nodosum can occur along with other diseases such as:
- peripheral arthritis.
People with TB complain:
- Respiratory problems.
Diagnosis and laboratory tests for erythema nodosum
If the doctor diagnoses erythema nodosum, he recommends some tests to find the underlying cause.
Among them are the following:
1. Blood analysis to look for evidence of inflammation and infection.
2. Examinations for streptococcal infection. For example, a throat swab. The swab is sent to a laboratory to see if there is an infection.
A certain blood test may show if the patient has had a streptococcal infection in the past.
In this case, the erythrocyte sedimentation rate (ESR) is also increased.
3. In a few cases, a biopsy is performed (the histological examination of a nodule to detect erythema nodosum).
4. Chest X-ray. If the doctor suspects TB or sarcoidosis, he will advise an X-ray of the thorax.
5. Other tuberculosis tests. The doctor may advise a special examination, the intradermal tuberculin test (Mantoux test).
The examination consists of a small injection into the arm.
The test is performed to determine whether the patient has been infected with tuberculosis.
If the patient suffers from coughing, the doctor may order a sample of the coughed up material to be sent to a laboratory for analysis.
6. Examinations for sarcoidosis. If the doctor suspects sarcoidosis, he can refer the patient to a specialist to confirm the suspicion, in this case to a rheumatologist.
Among the tests, there are tests of lung function (special studies of respiratory capacity).
Other possible investigations are:
- magnetic resonance imaging of the lungs,
- Bronchoscopy (the airways and lungs are examined via a telecamera in the endoscope).
7. Examination of stool samples. Infections can be detected by:
The doctor may advise this examination if the patient suffers from abdominal pain or diarrhea with concomitant erythema nodosum.
8. Intestinal examinations. If the doctor suspects inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease, they may recommend further examinations, such as a colonoscopy.
The doctor must exclude:
Treatment of erythema nodosum
The treatment initially provides for bed rest to reduce the following:
- Stress factors that can negatively affect the disease.
The doctor discontinues the medication that may have caused erythema nodosum.
If erythema nodosum is based on a bacterial infection, antibiotics are used. Oral tetracyclines have anti-inflammatory properties, shorten the duration of the disease and relieve discomfort.
You should put on compression bandages or wear compression stockings.
Anti-inflammatory drugs relieve the symptoms.
The doctor may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve the symptoms, such as:
- Indomethacin (Indoclir)
- Naproxen (Naproxen)
If the patient has numerous nodes, the doctor may prescribe funds that accelerate healing, such as:
- potassium iodite,
Natural remedies and homeopathic remedies
To alleviate the symptoms, can be applied to the nodules:
- drops of a mother tincture of nettle or calendula,
- Gel of aloe vera.
How long does the knot rose last? Prognosis for patients with erythema nodosum
It is important to know that erythema nodosum does not attack internal organs, even if it causes discomfort and often pain.
In the long run, the disease heals completely, even if it sometimes leads to recurrences.