Mastocytosis

And in very rare cases, mastocytosis can even present as leukemia (blood cancer). The symptoms that may occur are just as varied: for example, itching, pain, a sensation of heat, diarrhea, or anxiety attacks. That is why diagnosing mastocytosis is not easy, even for experienced doctors. The cause of the condition is an increase in the number of mast cells in the body and their overactivity. While there is no cure with medication, there are a number of effective treatments that can significantly reduce symptoms for most people affected.

Overview: What Is Mastocytosis?

Mastocytosis is a noncontagious disease that is usually benign. We distinguish between two forms:

• Cutaneous mastocytosis affects only the skin (“cutaneous” means “relating to the skin”). It usually presents as small reddish-brown spots or swellings that may itch or hurt; sometimes blisters may even develop. It used to be called urticaria pigmentosa. There are also localized forms characterized by an accumulation of mast cells that resemble a birthmark (known as mastocytomas). This form of skin disease primarily affects children and adolescents and often clears up on its own after some time
• Systemic mastocytosis is more common in adults. It often affects the bone marrow. Internal organs such as the intestines, liver, lymph nodes, and spleen may also be affected.

Both forms of mastocytosis have in common that there is an excess of active mast cells in the affected person’s body. These cells are produced in the bone marrow and are a type of white blood cell. They contain substances that react to pathogens and can trigger biological mechanisms. The disease is caused by a spontaneous, non-inherited mutation in the mast cells, which causes them to multiply abnormally or (more rarely) to grow uncontrollably (mast cell sarcoma). It’s also possible that they don’t follow their preprogrammed cell death and live too long.

Mastocytosis – Prevalence and Age

Mastocytosis is one of the very rare diseases. Experts estimate that in Switzerland and other European countries, fewer than ten people per million develop the disease each year. About two-thirds of people with mastocytosis are children, and one-third are adults. Boys and girls, as well as men and women, are equally affected. Familial clusters are rarely observed—if you have mastocytosis, there are likely no other cases among your relatives.

Among children with mastocytosis, the cutaneous form is the most common. Adults are most commonly affected by the benign (indolent) form of systemic mastocytosis. There are also aggressive, malignant variants, but these are very rare. Such aggressive forms usually develop de novo; it is extremely rare for a benign form to become malignant after several years.

Mastocytosis: Causes and Risk Factors

If you have mastocytosis, we won’t be able to say for certain why it happened to you, of all people. Your illness is not hereditary, and you did not catch it from anyone else. You are likely among the vast majority of people with mastocytosis who have developed a genetic change (mutation) for no apparent reason.

Perhaps your symptoms don’t appear out of the blue, but only when a specific trigger is present. There are people with mastocytosis who live symptom-free for years. The symptoms of their illness only become apparent when they are exposed to a specific situation. Trigger factors can include, for example:

• Sunlight
• Cold, Heat
• physical exertion
• emotional stress
• Alcohol
• certain foods or spices
• Insect bites
• Medications (for example, anesthetics, X-ray contrast agents, codeine, aspirin)

These trigger factors are by no means universal and vary greatly from person to person: There are certainly people with mastocytosis who can tolerate physical exertion, insect stings, or contrast agents without any problems, while others are highly sensitive to some or all of these factors.

Mastocytosis: Increased Risk with Other Treatments

If you are scheduled for surgery, as someone with mastocytosis, be sure to inform the hospital staff about your diagnosis. In many cases, the surgery can be performed without any problems. In some cases, however, the anesthetics may cause a severe allergic reaction in you. Specific medications used to reduce allergic reactions, taken as a preventive measure, can prevent this from happening.

The same applies if you are scheduled to receive an X-ray contrast agent—in this case as well, be sure to inform your doctor that you have mastocytosis.

Symptoms: Mastocytosis

Mastocytosis can manifest in different ways in affected individuals. There are mild, moderate, and severe cases. Sometimes only a single symptom is present, while in other cases several symptoms occur. The type of mastocytosis you have depends on where and to what extent the mast cells have multiplied in your body.

The most common symptoms of cutaneous mastocytosis are brownish-red patches. They often appear on the thighs, the abdomen and chest, or the back and pelvic area. The head—and thus the face as well—is usually left out. In adults, the spots are usually a few millimeters in size, while in children they tend to be a few centimeters in size. When you rub the spots, they usually start to itch. Often, after some time, they also develop into swelling (hives). The brownish-red, itchy skin patches occur in about 80 percent of all people with mastocytosis—not just in those who have the isolated cutaneous (skin-related) form of the disease.

Less common symptoms include abdominal pain, nausea, vomiting, and diarrhea. headaches, joint pain, and fatigue. Severe symptoms such as shortness of breath, fever, hot flashes, and circulatory collapse may also occur. Such severe symptoms occur when many mast cells are activated at the same time. Psychological symptoms such as anxiety, depression, sleep disturbances, or occasional drowsiness may also occur.

Even rarer are the aggressive and malignant forms of mastocytosis. They do not belong to the cutaneous form, but rather to the systemic form of this disease. In these cases, the mast cells displace the healthy cells in the organs, causing them to enlarge and impairing their function. This can occur, for example, in the liver, the spleen, or the lymph nodes. In extreme cases, the affected organs may fail.

Cases of mastocytosis in which changes in the blood count occur are particularly rare. There are various manifestations of this condition, such as an increased number of certain blood cells. There is an extremely rare form of leukemia (mast cell leukemia). In these cases, symptoms often include fever, general malaise, and loss of appetite and weight.

Mastocytosis: Diagnosis at Our Clinic

Does your skin have the typical brownish-red spots? However, these alone would not be proof of the disease. A test can provide more clarity: We stimulate one of the affected areas by scratching or rubbing it. If wheals then form on the skin (resulting in what is known as Darier’s sign), a diagnosis of cutaneous mastocytosis is virtually certain. However, the only way to be absolutely certain is through a skin biopsy—the removal of a skin sample. If it is examined in the lab and an accumulation of mast cells is found, this confirms the suspicion.

However, this does not yet tell us which form of mastocytosis you have—the purely cutaneous form (affecting only the skin) or the systemic form (also affecting internal organs). First, we take a thorough medical history, which means we ask about possible trigger factors or previous allergic reactions. We will also have your blood tested to determine how much tryptase it contains. Tryptase is a messenger substance released by mast cells. In cutaneous mastocytosis, the tryptase level is often still within the normal range, whereas in systemic mastocytosis, it is usually elevated.

Recently, specialized centers—including the USZ—have begun testing blood samples for the aforementioned mutation (c-KIT D816); if this mutation is detected, systemic mastocytosis is highly likely.

An even stronger indication that the systemic form of the disease is present comes from a bone marrow sample taken from the pelvic bone. If the bone marrow biopsy reveals an elevated number of mast cells, this is another sign of systemic mastocytosis. Another indication: More than a quarter of the mast cells examined have an atypical shape (oval or spindle-shaped instead of round). In addition, special stains on bone marrow can provide highly detailed information about the type of mast cells present in increased numbers.

In the systemic form of mastocytosis, the liver or spleen may become enlarged. If there is reason to suspect this, it is confirmed through an abdominal ultrasound and relevant laboratory test results.

Mastocytosis: Prevention, Early Detection, Prognosis

There is no direct way to prevent it. But there is an indirect way: If you know the trigger that causes your symptoms of mastocytosis, you can avoid that trigger. You may be hypersensitive to certain foods or medications without realizing it—in that case, you should try to identify them and avoid them.

It’s possible that several different triggers are at play in your case. The better you know them, the better you can try to avoid them. To find these triggers, you’ll probably need patience—but it can be worth it. In such cases, an allergy evaluation is often very helpful. It’s even possible that you could live without any symptoms at all, despite having mastocytosis.

Course and Prognosis of Mastocytosis

If mastocytosis develops at an early age, there is a more than 50 percent chance that the skin patches will fade or disappear completely by the age of 18. This often occurs—especially in isolated forms—even before children reach school age. Systemic mastocytosis, on the other hand, is less common in children, and its symptoms persist into adulthood.

If mastocytosis develops during puberty, in the vast majority of cases the symptoms do not go away on their own.

Very important: The vast majority of people with mastocytosis—more than 95 percent—have a completely normal life expectancy. It is reduced to less than five percent in patients suffering from an aggressive form of systemic mastocytosis or the very rare mast cell leukemia. In approximately 10 to 30 percent of people with systemic mastocytosis, bone density decreases (osteopenia) or bone loss occurs (osteoporosis) over the years.

The following applies to all people with mastocytosis: In most cases, the disease progresses slowly. For example, after they first appear, the skin spots may initially increase in number and then stop spreading, or they may continue to multiply only slowly. Even if your bone marrow or internal organs are affected, the course of your mastocytosis may remain stable for a long time. It cannot be completely ruled out that the symptoms will progress, but this is by no means certain.

Self-Help Groups

Talking with others who are going through the same thing can be a great source of support when coping with an illness. If you are looking for a suitable self-help group , you can get advice from Selbsthilfe Zürich. Selbsthilfe Zürich and the University Hospital of Zurich are partners in the national project “Health Literacy Through Self-Help-Friendly Hospitals.”

Mastocytosis: Possible Treatments

Although mastocytosis cannot be completely cured, its symptoms can be alleviated. As mentioned earlier, you should first try to identify your own triggers and avoid them as much as possible. In addition, depending on your specific condition, we can administer one or more of the following active ingredients.