Systemic Mastocytosis (SM) can affect many parts of the body, and it may look different from one person to another. To better understand how this condition presents, it’s helpful to distinguish between symptoms and manifestations—two related but different terms that describe how SM shows up in the body.
What’s the Difference Between Symptoms and Manifestations?
- Symptoms are what you feel—they are subjective experiences like pain, itching, nausea, or fatigue. Only you can describe your symptoms.
- Manifestations include your symptoms and other things doctors can observe or measure, like skin changes, organ swelling, or abnormal lab results. These are the visible or detectable effects of the disease.
When mast cells build up in the gastrointestinal (GI) tract, they can release histamine and other substances that throw off the normal functioning of the stomach and intestines which cause various signs and symptoms. These commonly occur along with symptoms in other parts of the body such as the skin and after exposure to a trigger.
Skin
The most common findings are multiple reddish-brown coin-sized spots found on the arms and legs but also chest, back and scalp. They can form a hive-like reaction when rubbed or become itchy during a reaction. This is called urticaria pigmentosa or “maculopapular cutaneous mastocytosis”. Other skin symptoms typically occur during a reaction and include:
- Flushing – patches of redness where the skin is warm to the touch- typically on the face and chest
- Itching – itching of the skin, which may be all over the body or only in specific places.
Digestive Tract (GI System)
Symptoms during a reaction in the GI tract may include common symptoms found in many other GI conditions. These include:
- Abdominal Bloating
- Pain or cramping in the abdomen: Pain that can be felt anywhere in the abdomen. It is often described as a “cramping feeling”.
- Nausea: feeling like you need to vomit often occuring with stomach discomfort
- Vomiting: Vomiting is when the contents of the stomach passes up the esophagus back into the mouth.
- Diarrhea: frequent and/or loose or watery stools.
- Loss of Appetite: This may be caused by pain and discomfort, nausea and/or vomiting.
- Weight Loss: Weight loss in Systemic Mastocytosis often occurs due to eating less food due to GI symptoms associated with eating.
- Enlarged Liver: Patients with more severe forms of mastocytosis may have enlarged livers with abnormal liver function tests and issues absorbing nutrients through the intestines. This is due to infiltration from abnormal mast cells. This is often detected on a radiology test such as a CT scan or is detected on a physical exam
Understanding both your symptoms and the manifestations of SM is important for you and your healthcare provider because it can help:
- Confirm a diagnosis of systemic mastocytosis
- Monitor how the condition may change over time
- Guide the right treatment options
- Track how well treatments are working
Your voice matters. If you are feeling new or worsening symptoms, make sure to share them with your healthcare provider. If you’ve had tests or scans, ask what those results mean in terms of how Systemic Mastocytosis is affecting your body.
Learn more about the types of SM and treatment options
Adapted from IFFGD Publication #902 “How does Systemic Mastocytosis Affect the Body?” and IFFGD Publication #903 “Manifestations of SM”
