Case Report and Review of the Literature: Bullous Skin Eruption After the Booster-Dose of Influenza Vaccine in a Pediatric Patient With Polymorphic Maculopapular Cutaneous Mastocytosis.

Vaccination is a well-known trigger for mast cell degranulation in subjects affected by mastocytosis. Nevertheless, there is no exact standardized protocol to prevent a possible reaction after a vaccine injection, especially for patients who have already presented a previous vaccine-related adverse event, considering that these patients frequently tolerate future vaccine doses. For this reason, we aim to share our experience at Meyer Children's University Hospital in Florence to raise awareness on the potential risk for future vaccinations and to discuss the valuable therapeutic strategies intended to prevent them, taking into account what is proposed by experts in literature. We describe the case of an 18-month-old female affected by a polymorphic variant of maculopapular cutaneous mastocytosis that presented an extensive bullous cutaneous reaction 24 hours after the second dose (booster dose) of inactivated-tetravalent influenza vaccine, treated with a single dose of oral corticosteroid therapy with betamethasone (0.1 mg/kg) and an oral antihistamine therapy with oxatomide (1 mg/kg/daily) for a week, until resolution. To the best of our knowledge, in the literature, no documented case of reaction to influenza vaccine in maculopapular cutaneous mastocytosis is described. Subsequently, the patient started a background therapy with ketotifen daily (0.05 mg/kg twice daily), a non-competitive H1-antihistamine, and a mast cell stabilizer (dual activity). A non-standardized pharmacological premedication protocol with an H1-receptor antagonist (oxatomide, 0.5 mg/kg) administered 12 hours before the immunizations, and a single dose of betamethasone (0.05 mg/kg) together with another dose of oxatomide (0.5 mg/kg) administered 2 hours before the injections was followed to make it possible for the patient to continue with the scheduled vaccinations. Indeed, no reactions were subsequently reported. Thus, in our experience, a background therapy with ketotifen associated with a premedication protocol made by two doses of oxatomide and a single dose of betamethasone was helpful to make possible the execution of the other vaccines. We suggest how in these children, it could be considered the idea of taking precaution when vaccination is planned, regardless of the kind of vaccine and if a dose of the same vaccine was previously received. However, international consensus needs to be reached to manage vaccinations in children with mastocytosis and previous adverse reactions to vaccines.

A New Digital Method for Counting Mast Cells in Cutaneous Specific Lesions of Mastocytosis: A Series of Adult Cases of Mastocytosis With Clinical-Pathological Correlations.

ABSTRACT: Cutaneous mastocytosis is characterized by the abnormal accumulation of mast cells in the skin. However, mast cell counting is not always easy and reproducible with classical methods. This work aims to demonstrate the reliability, usability, and virtues of a new software used on digital tablets for counting mast cells in cutaneous specific lesions of mastocytosis, to assess differences in mast cell counts between clinical subtypes of mastocytosis in the skin, and to consider the feasibility of applying a diagnostic mast cell count cutoff to urticaria pigmentosa, which is the most frequent form of cutaneous mastocytosis. Using a new digital tablet software that was accessible by multiple observers through its own wireless network and allowed high resolution of the image without data compression, we counted the number of mast cells on slides of patients and control skins immunostained for CD117. We found that our counting method was highly reproducible and that the new software allowed very quick counting. We evidenced strong differences in the mast cell count between most of the clinical subtypes of mastocytosis in the skin. However, when applied to a subset of patients with urticaria pigmentosa, a diagnostic cutoff in the mast cell count lacked sensitivity. Thus, our digital method for counting CD117-immunostained mast cells was highly accurate and was of a significant value for the diagnosis of mastocytosis in the skin. However, some subtypes with low mast cell counts will still require the application of additional diagnostic criteria.

Immunoreactivity for CD25 in gastrointestinal mucosal mast cells is specific for systemic mastocytosis.

Systemic mastocytosis (SM) is characterized by the accumulation of neoplastic mast cells in bone marrow and other organs. Gastrointestinal (GI) symptoms are common in both SM and cutaneous mastocytosis [urticaria pigmentosa (UP)], and are usually caused by the release of histamine and other inflammatory mediators. Occasionally, neoplastic mast cells may also directly infiltrate the GI tract. Previous studies have suggested that enumeration of the mast cells in GI biopsies may help establish the diagnosis of SM. However, mast cells have been reported to be increased in various inflammatory diseases, and mast cell density has not been systematically evaluated in other GI disorders. Recently, expression of CD25 by mast cells in bone marrow has been shown to be specific for SM. The purpose of this study was (1) to quantitate and compare mast cells in mucosal biopsies from patients with SM involving the GI tract, UP with GI symptoms, and a control group of diverse inflammatory disorders, and (2) to determine whether immunostaining for CD25 can be used to distinguish neoplastic from reactive mast cells in GI biopsies. Seventeen GI biopsies from 6 patients with SM; 17 GI biopsies from 5 patients with UP; and 157 control cases including 10 each normal stomach, duodenum, terminal ileum, and colon, Helicobacter pylori gastritis, bile reflux gastropathy, peptic duodenitis, celiac disease, Crohn disease, ulcerative colitis, lymphocytic colitis, and collagenous colitis, 20 biopsies from 16 patients with irritable bowel syndrome, 8 biopsies from 5 patients with parasitic infections, and 9 biopsies from 7 patients with eosinophilic gastroenteritis were immunostained for mast cell tryptase, c-kit (CD117), and CD25. Mucosal mast cells were quantitated, and the presence or absence of CD25 expression on mast cells was determined. In SM patients, mast cells in the small intestine and colon numbered >100/high-power field (HPF) in nearly all cases (mean 196/HPF; range 74 to 339). This was significantly higher than in GI biopsies from UP patients (mean 17/HPF; range 8 to 32, P<0.0001) and all inflammatory diseases (P<0.01). Mast cell density in other disorders ranged from a mean of 12/HPF in H. pylori gastritis to 47/HPF in parasitic infections. Interestingly, all SM biopsies (and none of the other cases) contained aggregates or confluent sheets of mast cells. In addition, mast cells in all SM cases were positive for CD25, whereas GI mucosal mast cells in UP and all other control cases were negative. In conclusion, quantitation of mast cells can be helpful to diagnose SM in GI mucosal biopsies, although mast cells are also markedly increased in parasitic infections. Aggregates or sheets of mast cells are only seen in SM. Immunoreactivity for CD25 in GI mucosal mast cells is specific for SM and can be used to confirm the diagnosis.

[Mastocytosis--mastcell proliferative disease risk of anaphylactic reaction]. / Mastocytoza--rozrostowa choroba komórek tucznych zwiazana z ryzykiem reakcji anafilaktycznej.

Mastocytosis is a group of rare diseases characterized by abnormal growth of mast cells in skin, bone marrow, liver, spleen, lymph nodes. Signs and symptoms result mostly from mast cells mediators and mast cells organ infiltration. Pathological examination proving mast cells infiltration is crucial for the diagnosis of disease. Therapy covers patient education and symptomatic treatment (antihistamine drugs and glicocortycoids). Attempts of interferon, cladribine, imatinib treatment are made. Aggressive forms of diseases require, chemiotherapy, bone marrow transplantation. All mastocytosis subjects should be equipped in adrenaline. The paper describes case of 52 years old woman who suffered from urticaria pigmenthosa, anaphylaxis, insect venom and food allergy. Diagnosis included bone marrow examinations (pathology, cytology, genetics, cytofotometry) tryptase level, skin prick tests and sIgE. Mastocytosis was diagnosed. Therapy included symptomatic treatment and immunotherapy. The paper describes also aims of the European Competence Network on Mastocytosis.

A new variant of mastocytosis: report of three cases clinicopathologically mimicking histiocytic and vasculitic disorders.

Cutaneous mastocytosis (CM) or urticaria pigmentosa is characterized by abnormal proliferation and accumulation of mast cells. Clinically, CM usually presents as symmetrically distributed red-brown macules or papules that develop weals, erythema and often pruritus on stroking (Darier's sign). The histological hallmark of the disease is an increase in oval to spindle-shaped mast cells in the dermis located around blood vessels and skin appendages. We describe three patients with a new clinicopathological type of CM, which clinically mimics a histiocytic disorder and histologically mimics leucocytoclastic vasculitis (LV). Three infants (two boys and one girl) developed generalized reddish-yellow-brown macules of 3-10 cm with occasional scaling and crusting on the trunk and extremities without further symptoms or organ involvement except variable itching. Histology revealed diffuse and dense dermal infiltrates of eosinophils, neutrophils and nuclear debris with perivascular accentuation, imitating LV. This infiltrate masked large epithelioid cells, positive for macrophage markers, which by special histochemical stains for metachromatic granules turned out to be mast cells. This is the first report of this new variant of CM, which may cause considerable diagnostic difficulties both clinically and histopathologically.

[Systemic mastocytosis]. / Mastocytoza ukladowa.

Mastocytosis is group of rare disorders characterized by abnormal mast cells growth. Pathology of the disease is unknown, mechanisms involved in mast cells delineation and growth are considered to play an important role. Unusual and broad spectrum of symptoms therefore requires cooperation of different specialists. The aim of the study was to assess diagnostic and therapeutic methods used in the Gdansk Mastocytosis Centre. 14 patients were studied (9 adults and 5 children). Bone marrow biopsy was performed in order to assess the stage of disease. Pathological, cytological, cytofotometry and genetic examination (C-KIT mutation) of the bone marrow were performed. Patients suffereing from food allergy and wasp venom anaphylaxis were diagnosed with skin prick tests and sIgE. All subjects suffered from urticaria pigmenthosa and anaphylaxis. Indolent mastocytosis was diagnosed in six subjects. Patients were treated with antihistamines, corticosteroids, cromones and immunotherapy with a marked reduction of symptoms. The experience of Gdansk Mastocytosis Centre indicates that mastocytosis is a rare and difficult to diagnose disease.

Hymenoptera sting anaphylaxis and urticaria pigmentosa: clinical findings and results of venom immunotherapy in ten patients.

BACKGROUND: Occasional patients with urticaria pigmentosa and anaphylaxis after Hymenoptera stings have been described. In this situation the question arises: Is anaphylaxis IgE-mediated or induced by pharmacologic mediator release from mast cells? METHODS: We investigated 10 patients with histologically confirmed urticaria pigmentosa and a history of anaphylaxis after honeybee or Vespula stings before and during immunotherapy with the respective venom. RESULTS: In eight of 10 patients, an elevated serum tryptase level was found. In two of 10 patients, no venom-specific IgE could be detected by either skin tests or RAST. Five patients had no detectable venom-specific serum IgE, and in the remaining patients the level was low (<1 Phadebas RAST unit). Venom immunotherapy was well tolerated and caused only one mild systemic reaction in a patient during the dose increase phase. Six patients were re-stung while receiving venom immunotherapy: only one had a mild systemic reaction (angioedema) after a Vespula sting. CONCLUSION: Anaphylactic symptoms after Hymenoptera stings in patients with urticaria pigmentosa are most often IgE-mediated but can occasionally be observed in the absence of IgE sensitization to venom allergens. Venom immunotherapy can be safely and successfully used in patients with urticaria pigmentosa and sting anaphylaxis.

Absence of MHC class II antigen on mast cells at sites of inflammation in human skin.

Since the presence of major histocompatibility complex (MHC) antigens has recently been reported on murine and human mast cells under various conditions, we have investigated their expression on mast cells in different types of cutaneous inflammation. Cryostat sections from lesional biopsies of patients with psoriasis, atopic eczema, chronic urticaria, lichen planus, bullous pemphigoid and urticaria pigmentosa were immunohistochemically stained with monoclonal antibodies against MHC class I and class II antigens using a double staining APAAP/toluidine blue methodology. While strongly positive staining with the antibody directed against MHC class I antigens was found on nearly all mast cells in normal skin and in inflammatory dermatoses, reactivity for HLA-DR and HLA-DQ antigens on mast cells could not be detected, except for less than 2% of cells with doubtful staining. Human mast cells therefore probably play no significant rôle as antigen-presenting cells in the conditions studied.

[Immunologic studies in chronic urticaria]. / Immunológiai vizsgálatok chronicus urticariában.

Chronic urticaria is considered to be a heterogeneous disease, which can be divided into several subclasses. The authors investigated 126 patients suffering from chronic urticaria with 41 of unknown origin. The aim of the present study was to work out a strategy for the complete investigation of patients with chronic urticaria. The findings of the immunological study modified the results obtained by medical assessment of the 126 chronic urticaria cases, diminished the number of the patient with chronic urticaria unknown etiology.

Two novel mast cell phenotypic markers, monoclonal antibodies Ki-MC1 and Ki-M1P, identify distinct mast cell subtypes.

In order to identify more specific or selective mast cell markers, the reactivity of two monoclonal antibodies, Ki-MC1 and Ki-M1P, was studied by immunohistochemistry in two human cell lines (mast cell line HMC-1, basophilic cell line KU812), in mast cells cultured from blood precursors, in adherent mononuclear cells from peripheral blood, and in mast cells of tissue sections from 13 urticaria pigmentosa lesions, five mastocytomas and five normal skin specimens. Toluidine blue staining, fluorescence staining with FITC-conjugated avidin, and immunohistochemical staining (APAAP) with other mast cell reactive monoclonal antibodies, was performed for comparison. Double staining with the APAAP method, using the Ki-antibodies and toluidine blue, was also carried out. Both Ki-antibodies showed reactivity for skin mast cells, but with a different staining pattern. In addition, the Ki-MC1 antibody did not react with the cell lines, and reacted only with a few peripheral blood mononuclear cells and cultured mast cells. In contrast, the Ki-M1P antibody reacted with almost all cultured mast cells and blood mononuclear cells, but stained only about one-half of lesional and one-fifth of normal skin mast cells. Ki-M1P also reacted with many toluidine blue-negative dermal cells, particularly in urticaria pigmentosa. Ki-MC1 antibody can thus be considered as a useful additional marker for normal skin mast cells. In contrast, the Ki-M1P antibody primarily identifies immature mast cells and monocytes/macrophages, suggesting that these cell types probably originate from the same bone marrow precursor.

Phenotypic characterization of skin lesions in urticaria pigmentosa and mastocytomas.

In order to identify possible cellular abnormalities in human mastocytosis, sections from 13 urticaria pigmentosa lesions and 5 mastocytomas were compared with 5 normal skin specimens using histochemical, enzyme histochemical and immunohistochemical techniques. All toluidine blue-positive mast cells also reacted with Fc epsilon RI and c-kit antibodies, almost all stained for tryptase, many for chymase and the myeloid workshop mast cell antibodies, few for Fc epsilon RII and none for the proliferation marker Ki-67. Urticaria pigmentosa lesions contained fewer epidermal Langerhans cells and a lower percentage of avidin-positive mast cells than mastocytomas and normal skin. Mastocytomas exhibited generally weaker staining for mast cell markers and mostly lacked Fc epsilon RI-bound IgE on mast cells and Langerhans cells, although the receptor was able to bind IgE in tissue sections. Most of the mast cell antibodies also reacted with other cell types. Only toluidine blue, avidin, tryptase and chymase stains were mast cell specific. Mast cells in mastocytosis thus differed only to a minor degree from normal mast cells, although distinct pathomechanisms may play a role in urticaria pigmentosa and mastocytosis.