Myxedema is a swelling of the skin and underlying tissues giving a waxy consistency, typical of patients with underactive thyroid glands.
The condition is usually associated with hypothyroidism, which includes weight gain, mental dullness and sensitivity to cold.
The myxedema crisis is an extreme complication of uncontrolled hypothyroidism.
It is usually seen in elderly women with undiagnosed hypothyroidism and is rare among young people.
The myxedema crisis is a potentially fatal complication of uncontrollable hypothyroidism that manifests as progressive mental deterioration such as lethargy, stupor, delirium or coma and multiple organ abnormalities.
The diagnosis of this strange phenomenon is hampered by its insidious onset.
Usually occurs when precipitating factors such as infection, disease, drugs, labor, etc., weaken the compensatory responses.
Despite the appropriate treatment, mortality ranges between 30 and 50 percent, especially in pregnancy.
Coma is usually observed in elderly women with undiagnosed hypothyroidism and is rare among young people.
Causes of myxedema
Myxedema is caused by an accumulation of tissue products, such as glycosaminoglycans, in the skin.
Myxedema is almost always a result of hypothyroidism. Several factors increase the risk of developing myxedema.
Not all people with risk factors will have myxedema. Risk factors for myxedema include:
- Autoimmune disorders (diseases in which the immune system attacks the body’s own tissues as foreign substances).
- Current or previous hypothyroidism
- Female gender and geriatric patients.
- Surgical removal of the thyroid gland.
- Therapeutic suppression of the activity of the thyroid gland.
- Although myxedema can also be caused by viral hypothyroidism, it is not known to be infectious or contagious.
Hypothyroidism occurs when the thyroid fails to function properly. It is caused by:
- Severe hypothyroidism not diagnosed or not treated.
- An autoimmune condition, which includes Hashimoto’s disease.
- Surgical removal of your thyroid (thyroidectomy).
- Radiation therapy to treat cancer.
- Certain medications, such as lithium or amiodarone (Pacerone).
- Iodine deficiency or an excess of iodine.
- The pregnancy.
- Medicines of the immune system, such as those used in the treatment of cancer.
- Graves disease.
- Autoimmune disease.
- Hereditary or congenital disorders.
Deposits of chains of sugar molecules (complex mucopolysaccharides) in the skin cause myxedema of the skin.
These compounds attract water, which leads to bloating. These changes in the skin are the result of hypothyroidism.
The myxedema crisis often occurs after a long history of hypothyroidism and is more common during the cold winter months. This crisis can be triggered when:
- Sudden illness appears, such as a heart attack or stroke.
- In cases of infections.
- Certain medications that suppress the central nervous system.
- Exposure to the cold.
Symptoms of the myxedema crisis
Symptoms of myxedema include thickening of the skin and other symptoms associated with hypothyroidism, including fatigue, weight gain, depression, dry skin and brittle hair, among others.
The thickening or swelling of the skin associated with myxedema is often described as edema without foaming.
In other words, if you press on the skin of the affected area and then remove your finger, you will not see an impression.
The function of thyroid hormones is to regulate your metabolism.
Myxedema is associated with other underactive thyroid symptoms, also called hypothyroidism, which includes lethargy, weight gain, fatigue, depression and sensitivity to cold, among others.
The most severe associated symptoms include swelling of the hands and face and decreased speech.
Rarely, serious or life-threatening symptoms, such as decreased breathing, low body temperature or lack of response, may be a sign of myxedema coma.
Myxedema is usually part of a larger group of symptoms associated with hypothyroidism.
Sometimes, any of these symptoms can be serious and include:
- Brittle hair or nails.
- Decreased sweating
- Dry or pale skin.
- Upset or lethargy.
- Musculoskeletal pain
- Sensitivity to cold.
- Thickening of the skin.
- Weakness (loss of strength)
- Weight gain.
- Rare or serious symptoms of myxedema.
Other symptoms occur more rarely with myxedema, but may indicate a more serious cause, type, or condition. These symptoms include:
- Decrease in the senses of taste and smell.
- Fullness in the neck (a mass in the neck, called a goiter, is a very rare symptom).
- Hair loss, including eyebrows.
- Decreased speech
Serious symptoms that can indicate a life-threatening condition include:
- Change in the level of consciousness or alertness, such as fainting or lack of response.
- Chest pain.
- Difficulty breathing or decreased respiratory rate.
- Low blood sugar (hypoglycemia).
- Low body temperature (hypothermia).
- Arrhythmias and disorders of coagulation.
The initial diagnosis is often based on the physical examination.
Usually, a TSH test is examined along with a thyroxine test (T4). This test measures the level of T4, a hormone produced directly by the thyroid.
If you have low levels of T4 along with a high level of TSH, the doctor may want to perform more tests to determine thyroid function and other conditions.
A computerized tomography of the brain will also be required.
The vital functions and level of consciousness are also continuously monitored during this process.
Hospitalization treatment will be needed with careful attention to hypotension, fluid replacement and replacement of steroids in an intensive care facility, until the patient is stable.
Your heart and breathing must be continuously monitored.
Hypotension, bradycardia, need for mechanical ventilation, hypothermia that does not respond to treatment, sepsis, sedative drug use, Glasgow coma coma scale lower.
As well as high scores of the severity scale and Sequential Bone Evaluation scores greater than 6, are significant predisposing factors of mortality in myxedema crises.
Treatment of myxedema
Myxedema is most often treated by treating the underlying cause of the hypothyroidism that led to the thickening and roughness of the skin.
Medication to replace reduced thyroid hormones is the most common treatment, and when properly dosed, it can stop the progression of myxedema.
The myxedema crisis is a medical emergency.
Once verified, TSH and T4 levels should begin treatment as soon as possible, as this leads to cardiogenic shock, respiratory depression, hypothermia and coma.
Patients are identified on the basis of a low index of suspicion with a careful history and an examination focused on the characteristics of hypothyroidism and the triggers.
Thyroid hormone replacement therapy is initiated if a myxedema crisis is suspected.
The route of treatment is through an intravenous line.
Studies have shown that the replacement of thyroid hormone through the ryles tube with a loading dose and maintenance therapy is as effective as intravenous therapy.
Replacements of thyroid hormone, such as levothyroxine, are prescribed at a low dose and are increased until hormone levels stabilize in the normal range.
Too much thyroid hormone or hormone replacement can cause symptoms of hyperthyroidism (overactive thyroid), which include rapid weight loss, palpitations and sweating.
Once the levels of the hormone T4 are restored, the symptoms become more manageable, although this may take several weeks.
Along with thyroid hormone replacement, treatments with steroids and other medications may be needed.
There are other types of treatment that focus on the symptoms of myxedema, which include:
- Compression stockings, which can help reduce the swelling associated with myxedema
- Topical corticosteroids, which can be used to decrease the inflammation associated with thickening of the skin in myxedema
Complications of myxedema
Myxedema coma is a potentially fatal complication of myxedema associated with severe hypothyroidism.
Myxedema coma is usually the result of severe untreated hypothyroidism in combination with a triggering event, such as an infection.
Complications of myxedema and hypothyroidism include:
- Adverse effects of hypothyroidism treatment.
- Give birth to a baby with birth defects.
- Heart disease.
- Heart failure.
- Spontaneous abortion.
- Osteoporosis (thinning and weakening of the bones).
- Susceptibility to infections.
- Unconsciousness and coma
Case series and case reports from the western world tell us that the incidence of myxedema crisis is around 0.22 million per year, but there is a shortage of epidemiological data from countries around the equator.
The epidemic of myxedema crisis follows the same pattern as in hypothyroidism and is more common in women and the elderly.