Medical Care
Therapy is conservative and aimed at symptom relief because the prognosis for most patients with cutaneous mastocytosis (CM) is excellent. None of the currently available therapeutic measures induces permanent involution of cutaneous or visceral lesions. Advise patients to avoid agents that precipitate mediator release, such as aspirin, nonsteroidal anti-inflammatory drugs, codeine, morphine, alcohol, thiamine, quinine, opiates, gallamine, decamethonium, procaine, radiographic dyes, dextran, polymyxin B, scopolamine, and D-tubocurarine.
H1 and H2 antihistamines decrease pruritus, flushing, and GI symptoms. Oral disodium cromoglycate may ameliorate cutaneous symptoms, such as pruritus, whealing, and flushing, as well as systemic symptoms, such as diarrhea, abdominal pain, bone pain, and disorders of cognitive function.
Cautious administration of aspirin to inhibit prostaglandin synthesis and maintain mast cell degranulation may be beneficial for patients with disease resistant to H1 and H2 antagonist therapy alone. The patient, premedicated with H1 and H2 antihistamines, may be started on small doses of aspirin, slowly titrated to reach a plasma level of 20-30 mg/100 mL. Initiate this treatment regimen in a controlled environment, because aspirin can induce mast cell mediator release and subsequent cardiovascular collapse.
Cutaneous lesions that involve a limited body area may be treated with a potent class 1 topical corticosteroid, with occlusion if required. Intralesional injections of small amounts of dilute corticosteroids may resolve skin lesions temporarily or indefinitely. The risk of skin atrophy and adrenocortical suppression resulting from the treatment is minimized by treating limited body areas during a single treatment session. Systemic corticosteroids are useful only in specific situations, such as ascites, malabsorption, and severe skin disease. Case reports have described complete remission of bullous mastocytosis with oral corticosteroids, [41] but systemic therapy is often disappointing because the primary mode of action of corticosteroids is redistribution rather than death of mast cells.
Oral psoralen plus UV-A (PUVA) therapy results in general and cosmetic benefits in the treatment of cutaneous mastocytosis, [42] particularly telangiectasia macularis eruptiva perstans (TMEP); however, risks are involved, such as skin cancer if more than 200 treatments are required. The manifestations of the disease usually recur several months after discontinuation of PUVA, but recurrences respond as well as the original lesions. PUVA rarely is required in children. Currently, PUVA is reserved for severe, unresponsive cases in adults. In a 2003 study, medium-dose UV-A1 therapy was shown to be as effective as high-dose UV-A1 in reducing symptoms and the number of mast cells in affected skin. [43] Narrowband UV-B has also been used. [44]
Medical alert bracelets should be made available, and an epinephrine self-injector demonstration should be performed and self-injector prescribed for patients with systemic mastocytosis or patients with episodes of vascular collapse. Patients with recurrent episodes of vascular collapse may be prophylactically placed on H1 and H2 antihistamines to lessen the severity of attacks. Episodes of vascular collapse may be spontaneous but have also occurred after stings from insects or after administration of iodinated contrast media for imaging studies. Premedication with antihistamines and corticosteroids is recommended before such procedures in patients at risk.
General anesthesia may be problematic in patients with systemic mastocytosis and perioperative modalities of these patients need to be considered. [45] The treatment algorithm for systemic mastocytosis is complex, and the condition is primarily managed by a hematologist. [45, 46]
Patients with aggressive systemic mastocytosis have disease-related organ dysfunction; interferon-alfa (with or without corticosteroids) can control dermatological, hematological, GI, skeletal, and mediator-release symptoms, but may be poorly tolerated. Cladribine has broad therapeutic activity, particularly when rapid debulking is indicated; the main toxicity is myelosuppression. Imatinib has a therapeutic role in the presence of an imatinib-sensitive KIT mutation or in patients with unmutated KITD816. [47]
Future novel therapy for cutaneous mastocytosis includes immune modulators. One successful case report from 2008 described treatment of progressive c-kit mutation cutaneous mastocytosis with imatinib, halting disease symptoms and progression and improving the length of disease course. [48] Imatinib is approved by the Food and Drug Administration for use in patients with aggressive systemic mastocytosis with organ dysfunction due to progressive infiltration of various organs by mast cells without D816V c-kit mutation or unknown c-kit mutation status. [49]
Masitinib may be superior to sunitinib as second-line therapy for patients who are imatinib resistant with systemic or severe cutaneous mastocytosis. [50]
Improvements in wheal formation and systemic symptoms may be seen with omalizumab, anti-immunoglobulin E therapy, in a patient with cutaneous mastocytosis and Ménière disease. [51, 52, 53, 54]
Pimecrolimus and other calcineurin inhibitors may be another potential therapy for mastocytosis and other mast cell-associated diseases. [55, 56]
Treatment of cutaneous mast cell lesions with the 585-nm flashlamp-pumped dye laser and the 532-nm Nd:YAG laser has been reported to provide cosmetic improvement. [57, 58]
Emergency resuscitation or hospitalization may be required for severe syncope or hypotensive shock resulting from the sudden severe degranulation of many mast cells.
Consultations
Consultation with a hematologist may be necessary for a bone marrow biopsy and staging. The WHO classification of systemic mastocytosis mandates a number of staging investigations to define the exact subtype of disease. Identification of "B" findings alone, such as the following, is indicative of a high systemic mastocytosis burden:
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Greater than 30% bone marrow mastocytosis burden
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Serum tryptase level greater than 200 ng/mL
The additional presence of "C" findings, such as the following, is diagnostic for the presence of aggressive disease. [2]
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Absolute neutrophil count less than 1000/µL (see the Absolute Neutrophil Count calculator)
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Hemoglobin value less than 10 g/µL
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Platelet count less than 100 000/µL
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Hepatomegaly with ascites and impaired liver function
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Palpable splenomegaly with hypersplenism
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Malabsorption with hypoalbuminemia and weight loss
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Large-sized osteolysis or severe osteoporosis causing pathologic fractures or life-threatening organopathy in other organ systems definitively caused by an infiltration of the tissue by neoplastic mast cells
Diet
Traditionally, physicians have advised cutaneous mastocytosis patients to avoid substances that induce mast cell mediator release, such as salicylates, crawfish, lobster, alcohol, spicy foods, hot beverages, and cheese. While evidence indicates that alcohol can cause adverse reactions, the role of the other foods mentioned above is hypothetical at this point and merits further investigation. [4]
Activity
Advise cutaneous mastocytosis patients to avoid certain physical stimuli, including emotional stress, temperature extremes, physical exertion, bacterial toxins, envenomation by insects to which the patient is allergic, and rubbing, scratching, or traumatizing the lesions of cutaneous mastocytosis.
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Urticaria pigmentosa lesions on the face of a child. Courtesy of Lee H. Grafton, MD.
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Urticaria pigmentosa lesions on the back of a child. Courtesy of Lee H. Grafton, MD.
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Lesion on the scalp of an infant.
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Lesion on the arm. Courtesy of Lee H. Grafton, MD.
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Blistering lesion.
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Hematoxylin and eosin stain revealing mast cells in the papillary dermis.
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Giemsa stain revealing mast cells.
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Positive Darier sign on a child's back.
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Urticaria pigmentosa on a child.
