Cutaneous mastocytosis is one of two types of mastocytosis, a rare disorder in which too many mast cells — a type of white blood cell that helps the immune system function properly — accumulate in the body. In cutaneous mastocytosis, mast cells build up in the skin, causing skin changes or lesions, while in systemic mastocytosis, mast cells multiply abnormally in the bone marrow, digestive tract, liver, spleen, or other organs. Cutaneous mastocytosis usually occurs in infants and toddlers but may affect adults, whereas systemic mastocytosis is found mostly in adults.e60dc2a1-f33c-4a05-9b50-8e3e8e59762928608ee1-b7c2-4f1c-8ad6-eb54833ac23f
Types of Cutaneous Mastocytosis Types There are three variants of cutaneous mastocytosis:e60dc2a1-f33c-4a05-9b50-8e3e8e5976291ae66eef-5229-4f17-b191-543decf92df8 Maculopapular Cutaneous Mastocytosis/Urticaria Pigmentosa This is the most common form of cutaneous mastocytosis and looks like small reddish-brown or brown spots on the skin that can be flat or elevated. At first, these may be mistaken for freckles. Plaque-like lesions — lesions greater than 1 centimeter in size — can also occur. The bumps can be classified into two types, monomorphic (all spots look similar) and polymorphic (the spots vary in appearance). Cutaneous Mastocytoma Usually present at birth, cutaneous mastocytoma involves an isolated mastocytoma (mast cell tumor) that’s about 2 to 5 centimeters in diameter. It usually goes away on its own, but it can be surgically removed if needed. Four cutaneous mastocytomas or more may become a diagnosis of maculopapular cutaneous mastocytosis. Diffuse Cutaneous Mastocytosis (DCM) In diffuse cutaneous mastocytosis, rather than individual lesions, there is an overall thickening and slight darkening of the skin; all the skin may become inflamed, rather than discrete areas. This is the most severe form of cutaneous mastocytosis and is more common in infants and babies under 2 years old.e60dc2a1-f33c-4a05-9b50-8e3e8e597629d6e19315-99ad-4bcf-954f-2bcb50bc053e
Signs and Symptoms of Cutaneous Mastocytosis Symptoms Cutaneous mastocytosis can cause a variety of symptoms, both on the skin and in other systems of the body. Skin Symptoms Skin symptoms of cutaneous mastocytosis can vary depending on the type and severity of the disease. They include:e60dc2a1-f33c-4a05-9b50-8e3e8e597629bfee0ee8-1bb6-4340-9574-f8541abb6bba Itchy or Inflamed Skin The skin can develop red, itchy patches or hives , or other changes, as described above. Rashes Maculopapular cutaneous mastocytosis often results in dark spots or bumps that may itch or swell when scratched. Flushing Some people experience redness or flushing of the skin, especially after exposure to heat, eating certain foods, or stress. Blistering In more severe cases, especially in diffuse cutaneous mastocytosis, the skin may blister and become painful. This only happens in babies and young children. Systemic Symptoms Even though mast cell overaccumulation occurs only in the skin in cutaneous mastocytosis, it can cause symptoms in other parts of the body, particularly the gastrointestinal system. Children with cutaneous mastocytoma may also have:e60dc2a1-f33c-4a05-9b50-8e3e8e597629e50fe0a6-5556-44c1-9e98-3f2649df9a95 Diarrhea Abdominal pain Peptic ulcers Children with diffuse cutaneous mastocytosis may experience:e60dc2a1-f33c-4a05-9b50-8e3e8e597629bfee0ee8-1bb6-4340-9574-f8541abb6bba Diarrhea Gastrointestinal bleeding Decreased blood pressure
Causes and Risk Factors for Cutaneous Mastocytosis Causes In many cases, mastocytosis is caused by several mutations in a gene called KIT, which is responsible for regulating the growth and function of mast cells. This change in the KIT gene is usually not inherited.e60dc2a1-f33c-4a05-9b50-8e3e8e597629cf9cbd35-256f-41af-9377-d31956b92767 Risk factors for cutaneous mastocytosis include: Age Cutaneous mastocytosis most commonly appears in childhood, often before the age of 2. Environmental Triggers External factors like temperature changes, stress, infections, and certain medications may trigger symptoms.
How Is Cutaneous Mastocytosis Diagnosed? Diagnosis Depending on the age of the person and the suspected type of cutaneous mastocytosis, diagnosis may involve a combination of the following: Physical Exam The skin will be examined to check for characteristic lesions like urticaria pigmentosa. Darier’s Sign If maculopapular cutaneous mastocytosis/urticaria pigmentosa lesions are found, the provider may lightly rub or scratch a small area of the affected skin. The development of redness or hives over or around the lesion within about five minutes is called Darier’s sign and suggests the presence of mast cells within the lesion.e60dc2a1-f33c-4a05-9b50-8e3e8e59762954c10eb4-acf4-43a1-910f-8f675ce2ea3d Skin Biopsy A small sample of skin may be taken and examined under a microscope to confirm the presence of excessive mast cells. Blood Tests Measuring the levels of tryptase, a protein released by mast cells, can help confirm the diagnosis, though it’s primarily used to assess systemic mastocytosis. Genetic Tests In some cases, additional tests, such as genetic testing, may be used to check for mutations in the KIT gene.e60dc2a1-f33c-4a05-9b50-8e3e8e597629328d3d6a-15da-457d-a0c0-dc7c63fb40a2 Bone Marrow Biopsy In adults, this may be used to look for unusual numbers of mast cells in the bone marrow. Because pediatric mastocytosis is usually limited to the skin and spontaneously improves as children get older, most infants and children don’t have to have a bone marrow biopsy performed.
Treatment and Medication Options for Cutaneous Mastocytosis Treatment While there is no cure for cutaneous mastocytosis, there are treatments available to manage symptoms and improve quality of life. Epinephrine for Anaphylaxis Although the risk of anaphylaxis is small compared to people with systemic mastocytosis, people with cutaneous mastocytosis (or their caregivers) should have at least two doses of epinephrine in self-injectable form or nasal spray available at all times. Medication Options The following medications may help relieve symptoms in cutaneous mastocytosis:e60dc2a1-f33c-4a05-9b50-8e3e8e5976296deaf5da-9e82-44c3-aa17-bddfd158c7d3 Antihistamines These are the mainstays of treatment to control symptoms like itching, flushing, and rashes. Cromolyn Sodium This medication can help stabilize mast cells, preventing the release of histamine and other chemicals. It can help with gastrointestinal symptoms. Leukotriene Modifiers These drugs help control symptoms like itching and abdominal discomfort when antihistamines alone aren’t enough. Proton Pump Inhibitors These drugs are helpful for treating stomach acid issues. Steroids Systemic glucocorticoids may be used for severe symptoms, but they aren’t recommended for routine or maintenance management. Short-term use of topical steroids may help reduce inflammation and itching in some patients. Surgery Removing mastocytomas (if possible) may cure cutaneous mastocytosis, but it isn’t recommended unless the symptoms can’t be controlled in any other way.e60dc2a1-f33c-4a05-9b50-8e3e8e59762914a65a25-1491-4c6c-9b2a-86d4a6f2afa5 Phototherapy In severe cases, ultraviolet light therapy (UVB) or psoralen plus ultraviolet A (PUVA) may be used to reduce the number of mast cells and control symptoms.e60dc2a1-f33c-4a05-9b50-8e3e8e5976295b777b24-45ff-46d0-8653-b9cb72190d42
Prevention of Cutaneous Mastocytosis Prevention While there is no known way to prevent cutaneous mastocytosis, managing triggers can help prevent flare-ups and keep symptoms under control.e60dc2a1-f33c-4a05-9b50-8e3e8e59762946074a06-97ec-44f8-b404-d224b8d31fb1
Lifestyle Changes for Cutaneous Mastocytosis Lifestyle Changes Although prevention of cutaneous mastocytosis isn’t possible, there are ways to limit exposure to factors that can activate mastocytosis symptoms or trigger an anaphylactic reaction. Avoiding Triggers Many potential triggers for cutaneous mastocytosis have been identified, but not everyone with the condition reacts in the same way. Potential triggers include the following:e60dc2a1-f33c-4a05-9b50-8e3e8e5976299753b548-593e-4b0a-ace2-cf2c12d8665b Friction on the skin caused by touching or rubbing Being stung or bit by an insect, especially ants , wasps , and bees Alcohol Heat and humidity Physical exertion and stress Spicy foods, alcohol, and certain medications Dietary Changes Current guidelines don’t recommend a specific diet, but identifying food triggers can help manage symptoms or allergic reactions. Foods that are more reactive include monosodium glutamate (MSG), alcohol, shellfish, artificial food dyes and flavorings, preservatives, pineapples, tomatoes and tomato-based products, and chocolate. However, these foods might not be an issue for everyone, and some people may have problems with other foods. Consulting a nutritionist or allergist can be helpful in identifying specific triggers through an elimination diet . It’s also important to eat a healthy, balanced diet.e60dc2a1-f33c-4a05-9b50-8e3e8e59762908308c10-c2b8-477f-a7e6-6e5c4843a205
Cutaneous Mastocytosis Prognosis Prognosis and Outlook The most common type of cutaneous mastocytosis, maculopapular cutaneous mastocytosis/urticaria pigmentosa, goes away by puberty in about half of the children who have it. Symptoms usually get better in others as they become adults.e60dc2a1-f33c-4a05-9b50-8e3e8e5976294e998aa3-f57a-44b5-a3d5-14fff4819bf9 Overall, the prognosis for all types of cutaneous mastocytosis is excellent for children who experience the onset of skin lesions within the first two years of life, because it usually goes away. When cutaneous mastocytosis develops after age 2 or in adulthood, it tends to persist. Late-childhood onset of the disease is associated with an increased risk of developing systemic mastocytosis.e60dc2a1-f33c-4a05-9b50-8e3e8e597629381199d1-fbda-47e0-9151-22d2d6024fe8 A high percentage of adults with skin lesions have systemic mastocytosis, with the majority having indolent systemic mastocytosis.e60dc2a1-f33c-4a05-9b50-8e3e8e597629f255c827-774d-4192-9eb1-7554a1836608
Complications of Cutaneous Mastocytosis Complications Though rare, some individuals with cutaneous mastocytosis may be at risk for severe allergic reactions (anaphylaxis), especially if they have high levels of tryptase, or if they experience systemic involvement.
Research and Statistics: How Many People Have Cutaneous Mastocytosis? Research and Statistics Cutaneous mastocytosis usually affects infants and toddlers but may affect adults. The global prevalence of any type of mastocytosis, including cutaneous mastocytosis, is about 1 in 10,000 to 20,000 people, though some experts believe the condition is underdiagnosed.e60dc2a1-f33c-4a05-9b50-8e3e8e59762971748869-ba44-440d-9e8e-4127893f3f14
Support for People With Cutaneous Mastocytosis Support The Mast Cell Disease Society This advocacy group offers online and Facebook-based support groups and an online forum. It also has an online physician finder and a variety of downloadable reference guides for patients.
The Takeaway Cutaneous mastocytosis is a rare condition in which abnormal mast cells accumulate in the skin, causing symptoms like rashes, itching, and flushing. It primarily affects infants and young children, though it can develop in adults. Medical treatments and lifestyle changes won’t cure the disease, but they can help manage symptoms.
Resources We Trust Cleveland Clinic: MastocytosisLeukemia & Lymphoma Society: MastocytosisNational Organization for Rare Disorders: MastocytosisThe Mast Cell Disease Society: Cutaneous Mastocytosis VariantsAmerican Academy of Allergy, Asthma & Immunology: Mast Cell Disorders and Mastocytosis Videos
