Prevalence of hypersensitivity reactions in various forms of mastocytosis: A pilot study of 2485 adult patients with mastocytosis collected in the ECNM registry.

BACKGROUND: Hypersensitivity reactions (HR) are common in mastocytosis. However, little is known about triggers and risk factors. The registry of the European Competence Network on Mastocytosis (ECNM) enables reliable studies in a larger cohort of mastocytosis patients. We assessed prevalence, triggers and risk factors of HR in adults with mastocytosis in the ECNM registry. METHODS: Data were collected in 27 ECNM centers. We analyzed potential triggers (Hymenoptera venoms, food, drug, inhalant and others) and risk factors at diagnosis and during follow-up. The study group consisted of 2485 adults with mastocytosis, 1379 women (55.5%) and 1106 men (44.5%). Median age was 48.2 years (range 18-91 years). RESULTS: Nine hundred and forty eight patients (38.1%) reported one or more HR`. Most common triggers were Hymenoptera venoms in cutaneous mastocytosis (CM) and indolent systemic mastocytosis (ISM), whereas in advanced SM (advSM), most common elicitors were drugs, including nonsteroidal anti-inflammatory agents and penicillin. In multivariate analyses, tryptase level < 90 ng/mL, <15% infiltration by mast cells in bone marrow biopsy-sections, and diagnosis of ISM were identified as independent risk factors for HR. For drug-induced HR, prominent risk factors were advSM and high tryptase levels. New reactions were observed in 4.8% of all patients during 4 years follow-up. CONCLUSIONS: HR are mainly triggered by Hymenoptera venoms in patients with CM and ISM and by drugs in patients with advSM. Tryptase levels <90 ng/mL, mast cell bone marrow infiltration <15%, and WHO category ISM are predictors of HR. New HR occur in 4.8% of all patients within 4 years.

Serum chemistry profiling and prognostication in systemic mastocytosis: a registry-based study of the ECNM and GREM.

Certain laboratory abnormalities correlate with subvariants of systemic mastocytosis (SM) and are often prognostically relevant. To assess the diagnostic and prognostic value of individual serum chemistry parameters in SM, 2607 patients enrolled within the European Competence Network on Mastocytosis (ECNM) and 575 patients enrolled within the German Registry on Eosinophils and Mast Cells (GREM) were analyzed. For screening and diagnosis of SM, tryptase was identified as the most specific serum parameter. For differentiation between indolent and advanced SM (AdvSM), the following serum parameters were most relevant: tryptase, alkaline phosphatase (AP), ß2-microglobulin, lactate dehydrogenase (LDH), albumin, vitamin B12, and C-reactive protein (P<0.001). With regard to subvariants of AdvSM, an elevated LDH ≥260U/L was associated with multi-lineage expansion (leukocytosis, r=0.37, P<0.001; monocytosis, r=0.26, P<0.001) and the presence of an associated myeloid neoplasm (P<0.001), whereas tryptase levels were highest in mast cell leukemia (MCL vs. non-MCL, 308 µg/L vs. 146 µg/L, P=0.003). Based on multivariable analysis, the hazard-risk weighted assignment of 1 point to lactate dehydrogenase (HR 2.1 [95% CI 1.1-4.0], P=0.018) and 1.5 points each to ß2-microglobulin (HR 2.7 [95% CI 1.4-5.4], P=0.004) and albumin (HR 3.3 [95% CI 1.7-6.5], P=0.001) delineated a highly predictive three-tier risk classification system (0 points, 8.1 years vs. 1 point, 2.5 years, ≥1.5 points, 1.7 years; P<0.001). Moreover, serum chemistry parameters enabled further stratification of IPSM-AdvSM1/2 risk-score classified patients (P=0.027). In conclusion, serum chemistry profiling is a crucial tool in the clinical practice supporting diagnosis and prognostication of SM and its subvariants.

Burden of Disease in the Real-Life Setting of Patients with Atopic Dermatitis: Italian Data From the MEASURE-AD Study.

INTRODUCTION: Atopic dermatitis (AD) is a chronic inflammatory skin disease that negatively impacts the quality of life and work productivity of patients. OBJECTIVES: We sought to evaluate the real-world burden of AD patients in Italy. METHODS: This sub-analysis of the MEASURE-AD multicountry study conducted between December 2019-2020 included patients diagnosed with moderate-to-severe AD eligible for or receiving systemic therapy in the previous 6 months. During a single visit, physician and patient-reported questionnaires were used. RESULTS: A total of 118 adult patients were enrolled and 57.6% (N = 68) of patients had moderate-to-severe AD at the time of enrolment according to the Eczema Area and Severity Index. Sleep disorders interfered with daily function in the previous week in 58.5% (N = 69) of patients, pruritus was severe in 50% (N = 59) and 42.4% (N = 50) reported a flare lasting >7 days in the previous 6 months. According to the Dermatology Quality of Life Index, 37.3% (N = 44) of patients reported a severe impact of AD and approximately 10% had clinical depression/anxiety. Current drug therapy was considered inadequate in controlling AD in 26.3% (N=31) of patients. Work activity impairment was 38.6±31.7% and monthly AD-related expenses were 148.6±134.6 Euros per patient. CONCLUSIONS: This real-life study documents a high burden of disease in patients with moderate-severe AD in Italy.

A Case of Lip Psoriasis in a 14-Year-Old Boy Successfully Treated with Adalimumab.

Psoriasis is a common chronic skin disease mainly located in areas of friction. Psoriasis of the lips as an exclusive presentation is rare and often misdiagnosed. Different anti-psoriatic therapies have been proposed, but the literature is limited to case studies with partial results. Biologic therapies have revolutionized the management of many dermatologic conditions, including psoriasis, and they are approved for pediatric use. We report the case of a 14-year-old boy with a 2-year history of white-yellowish scaling lesions on his lips, without intraoral involvement. Lip biopsy showed a psoriasiform pattern. Treatment with adalimumab 40 mg every other week was started, and after 6 months of therapy, we obtained a complete remission of the patient's lip psoriasis.

Peristomal Skin Complications: Detailed Analysis of a Web-Based Survey and Predictive Risk Factors.

Patients with a stoma are at risk of developing peristomal skin complications (PSCs) that can negatively impact their quality of life. This study aims to identify potential risk factors for dermatitis, pruritis/xerosis, infections, and ulcerations among patients with a stoma and evaluate preventive measures. This cross-sectional study involved data regarding 232 Italian patients with a stoma. A questionnaire was used to collect patient characteristics, comorbidities, and stoma management data. The most frequent PSCs observed were dermatitis and pruritis/xerosis in approximately 60% of patients. Psoriasis was strongly correlated with dermatitis, while being overweight or obese increased the risk of pruritis/xerosis. Class 2 obesity and atopic dermatitis were associated with an increased risk of infections. Being underweight, completely nonautonomous, and having inflammatory bowel disease were associated with a higher risk of ulcerations, while radiotherapy was a strong risk factor for ulceration. Preventive measures such as using hydrocolloid barriers, TNT gauze cleansing, and low pH detergent were effective in preventing dermatitis. Appropriate stoma care and maintenance, including the use of protective film and careful monitoring of weight and comorbidities, are crucial in minimizing the risk of complications associated with a stoma.

Paraviral bullous eruption in a 7-year-old child during acute Epstein-Barr virus infection: A case report.

We present the case of a child developing widespread vesicle-bullous lesions during an acute and symptomatic Epstein-Barr Virus infection. Antibody serology, biopsy, and direct immunofluorescence allowed the diagnosis of a paraviral bullous eruption. To our knowledge, this is the first report of bullous eruption following Epstein-Barr virus infection in childhood.

Severe trichothiodystrophy and cardiac malformation in a newborn carrying a novel GTF2H5 homozygous truncating variant.

We report a newborn patient with trichothiodystrophy-3 (TTD3) caused by a novel homozygous variant in the GTF2H5 gene. His severe phenotype included congenital ichthyosis, complex posterior cranial fossa anomaly, life-threatening infections, bilateral cryptorchidism, and, notably, a complex cardiac malformation, which is unprecedented in TTD3 patients.

Prognostic Impact of Organomegaly in Mastocytosis: An Analysis of the European Competence Network on Mastocytosis.

BACKGROUND: Organomegaly, including splenomegaly, hepatomegaly, and/or lymphadenopathy, are important diagnostic and prognostic features in patients with cutaneous mastocytosis (CM) or systemic mastocytosis (SM). OBJECTIVES: To investigate the prevalence and prognostic impact of 1 or more organomegalies on clinical course and survival in patients with CM/SM. METHODS: Therefore, 3155 patients with CM (n = 1002 [32%]) or SM (n = 2153 [68%]) enrolled within the registry of the European Competence Network on Mastocytosis were analyzed. RESULTS: Overall survival (OS) was adversely affected by the number of organomegalies (OS: #0 vs #1 hazard ratio [HR], 4.9; 95% CI, 3.4-7.1, P < .001; #1 vs #2 HR, 2.1, 95% CI, 1.4-3.1, P < .001; #2 vs #3 HR, 1.7, 95% CI, 1.2-2.5, P = .004). Lymphadenopathy was frequently detected in patients with smoldering SM (SSM, 18 of 60 [30%]) or advanced SM (AdvSM, 137 of 344 [40%]). Its presence confered an inferior outcome in patients with AdvSM compared with patients with AdvSM without lymphadenopathy (median OS, 3.8 vs 2.6 years; HR, 1.6; 95% CI, 1.2-2.2; P = .003). OS was not different between patients having organomegaly with either ISM or SSM (median, 25.5 years vs not reached; P = .435). At time of disease progression, a new occurrence of any organomegaly was observed in 17 of 40 (43%) patients with ISM, 4 of 10 (40%) patients with SSM, and 33 of 86 (38%) patients with AdvSM, respectively. CONCLUSIONS: Organomegalies including lymphadenopathy are often found in SSM and AdvSM. ISM with organomegaly has a similar course and prognosis compared with SSM. The number of organomegalies is adversely associated with OS. A new occurrence of organomegaly in all variants of SM may indicate disease progression.

Mast cell leukemia: clinical and molecular features and survival outcomes of patients in the ECNM Registry.

Mast cell leukemia (MCL) is a rare subtype of systemic mastocytosis defined by ≥20% mast cells (MC) on a bone marrow aspirate. We evaluated 92 patients with MCL from the European Competence Network on Mastocytosis registry. Thirty-one (34%) patients had a diagnosis of MCL with an associated hematologic neoplasm (MCL-AHN). Chronic MCL (lack of C-findings) comprised 14% of patients, and only 4.5% had "leukemic MCL" (≥10% circulating MCs). KIT D816V was found in 62/85 (73%) evaluable patients; 9 (11%) individuals exhibited alternative KIT mutations, and no KIT variants were detected in 14 (17%) subjects. Ten evaluable patients (17%) had an abnormal karyotype and the poor-risk SRSF2, ASXL1, and RUNX1 (S/A/R) mutations were identified in 16/36 (44%) patients who underwent next-generation sequencing. Midostaurin was the most common therapy administered to 65% of patients and 45% as first-line therapy. The median overall survival (OS) was 1.6 years. In multivariate analysis (S/A/R mutations excluded owing to low event rates), a diagnosis of MCL-AHN (hazard ratio [HR], 4.7; 95% confidence interval [CI], 1.7-13.0; P = .001) and abnormal karyotype (HR, 5.6; 95% CI, 1.4-13.3; P = .02) were associated with inferior OS; KIT D816V positivity (HR, 0.33; 95% CI, 0.11-0.98; P = .04) and midostaurin treatment (HR, 0.32; 95% CI, 0.08-0.72; P = .008) were associated with superior OS. These data provide the most comprehensive snapshot of the clinicopathologic, molecular, and treatment landscape of MCL to date, and should help further inform subtyping and prognostication of MCL.

Update on the Management of Pediatric Psoriasis: An Italian Consensus.

INTRODUCTION: Psoriasis affects children with a considerable burden in early life. Treating pediatric psoriasis is challenging also because of the lack of updated specific guidelines. With the recent approval of several biologics for pediatric psoriasis and the ongoing COVID-19 pandemic, the management of young psoriatic patients is facing major changes. A revision of treatment recommendations is therefore needed. METHODS: In September 2021, a board of six Italian dermatologists convened to update treatment recommendations. The board issued evidence- and consensus-based statements covering relevant areas of pediatric psoriasis, namely: assessment of psoriasis severity, management of children with psoriasis, and treatment of pediatric psoriasis. To reach consensus, the statements were submitted to a panel of 24 experts in a Delphi process performed entirely via videoconference. A treatment algorithm was produced. RESULTS: There was full consensus that psoriasis severity is determined by the extension/severity of skin lesions, site of lesions, and impact on patient quality of life. Agreement was reached on the need for a multidisciplinary approach to pediatric psoriasis and the importance of patient/parents education. The relevance of vaccinations, including COVID-19 vaccination, for psoriatic children was acknowledged by all participants. Management issues that initially failed to reach consensus included the screening for psoriasis comorbidities and early treatment with biologics to prevent them and the use of telemedicine to facilitate patient follow-up. There was full consensus that topical corticosteroids are the first choice for the treatment of mild pediatric psoriasis, while phototherapy and systemic therapy are used in children with moderate-severe psoriasis. According to the proposed treatment algorithm, biologics are the first line of systemic therapy. CONCLUSIONS: Targeted systemic therapies are changing the treatment of moderate-severe pediatric psoriasis, while topical corticosteroids continue to be the first choice for mild disease. Children-centered research is needed to further improve the treatment of pediatric psoriasis.

Narrative review on the management of moderate-severe atopic dermatitis in pediatric age of the Italian Society of Pediatric Allergology and Immunology (SIAIP), of the Italian Society of Pediatric Dermatology (SIDerP) and of the Italian Society of Pediatrics (SIP).

Currently, there are a few detailed guidelines on the overall management of children and adolescents with moderate-severe atopic dermatitis. AD ​​is a complex disease presenting with different clinical phenotypes, which require an individualized and multidisciplinary approach. Therefore, appropriate interaction between primary care pediatricians, pediatric allergists, and pediatric dermatologists is crucial to finding the best management strategy. In this manuscript, members of the Italian Society of Pediatric Allergology and Immunology (SIAIP), the Italian Society of Pediatric Dermatology (SIDerP), and the Italian Society of Pediatrics (SIP) with expertise in the management of moderate-severe atopic dermatitis have reviewed the latest scientific evidence in the field. This narrative review aims to define a pathway to appropriately managing children and adolescents with moderate-severe atopic dermatitis.

Contact allergy in children with and without atopic dermatitis: An Italian multicentre study.

BACKGROUND: Contact allergy and atopic dermatitis (AD) are both common inflammatory T cell-mediated diseases and many factors may influence the prevalence of contact allergy in AD patients. In children, their possible correlation was debated with conflicting results. OBJECTIVES: The present study aimed to assess the prevalence of contact sensitivity in children and to investigate the association with AD. MATERIALS AND METHODS: A retrospective multicentre study on children aged from 0 to 14 years patch tested between January 2017 and December 2018 was performed. Children were consecutively patch tested with the SIDAPA (Società Italiana Dermatologia Allergologica Professionale Ambientale) baseline series. RESULTS: Among the 432 children investigated for contact allergy, 125 (28.9%) showed a positive reaction to at least one of the allergens tested, with a higher prevalence of positive patch test reactions in girls (32.3%) than in boys (25.0%). The most frequent contact allergens were nickel sulphate (10.2%), cobalt chloride (6.7%), methylisothiazolinone (3.7%), fragrance mix-2 (3.2%), potassium dichromate (2.8%), fragrance mix-1 (2.1%) and methylchloroisothiazolinone/methylisothiazolinone (2.1%). One-hundred-three children (23.8%) suffered from AD showing a higher prevalence of positive patch test (36.9%) compared to children without AD (26.4%). CONCLUSIONS: Despite the topic being still controversial, the present study suggests a consistent prevalence of contact allergy among children with higher sensitivity rate among children with AD than without AD.

Effectiveness and Safety of Adalimumab, Etanercept and Ustekinumab for Severe Psoriasis in Children Under 12 Years of Age: A French-Italian Daily Practice Cohort (BiPe Jr).

INTRODUCTION: Biological therapies are valuable treatments for severe psoriasis. Children aged under 12 years are underrepresented in therapeutic trials for these drugs. The objective of the 'BiPe Jr' cohort study was to evaluate the drug survival, effectiveness, tolerance and switching patterns of biological therapies in children under 12 years of age with psoriasis. METHODS: We conducted a multicentre retrospective study of children with psoriasis who received at least one injection of a biological agent, even off-licence, before the age of 12 years in France and Italy, collecting the data between April and August 2021. The data collected were from March 2012 up to August 2021. RESULTS: In total, 82 children (mean age: 9.1 years; females: 61.0%) received 106 treatments. The drugs administered were adalimumab (n = 49), etanercept (n = 37), ustekinumab (n = 15), anakinra (n = 2), infliximab (n = 2) and secukinumab (n = 1). The most common form of psoriasis was plaque psoriasis (62.9%). The Physician Global Assessment and the Psoriasis Area Severity Index (PASI) scores decreased significantly from baseline to 3 months after treatment initiation for the three main biological drugs; PASI went from 14.1 ± 9.4 to 4.1 ± 11.3 for adalimumab (p = 0.001), 14.9 ± 9.3 to 5.1 ± 4.0 for etanercept (p = 0.002) and 11.6 ± 8.3 to 2.6 ± 2.2 for ustekinumab (p = 0.007). A trend towards higher 2-year maintenance rates was observed for ustekinumab and adalimumab, compared with etanercept (p = 0.06). 52 children discontinued their biological therapy, most frequently due to inefficacy (n = 28) and remission (n = 14). Seven serious adverse events (SAEs) were reported, including four severe infections. DISCUSSION: Our analyses of drug survival and treatment patterns, combined with those of previous studies conducted in older children, indicate that there is a trend towards higher 2-year survival rates of ustekinumab and adalimumab. The SAEs identified were rare, but highlight the need for increased vigilance concerning infections. Overall, the biological therapies showed good effectiveness and safety profiles when used in daily practice for the treatment of young children with psoriasis.

Pediatric impetigo: an expert panel opinion about its main controversies.

Bacterial impetigo is one of the most common skin infection in childhood. Uncertainty exists about its management. This article offers practical suggestions, given the existing evidence and experts' opinions, for correctly managing pediatric impetigo in both hospital and ambulatory settings. Italian physicians with an expertise on pediatric impetigo appointed a working group. A preliminary literature search using Pubmed/MEDLINE and Cochrane Library databases has been performed. The most common controversial issues about pediatric impetigo have been identified and then discussed from multidisciplinary perspectives, according to the 'structured controversy' methodology, a technique discovered and designed to get engaged in a controversy and then guide participants to seek consensus. The expert panels identified 10 main controversies about pediatric impetigo. All of them have been discussed from dermatological, pediatric, pharmacological and microbiological points of view reaching consensus. Each controversy has been revised thus giving practical issues for an easy use in clinical practice. Based on clinical experts' opinion, local epidemiology and literature review this article offers practical suggestions for the management of pediatric impetigo trying to reduce uncertainty in this setting of care.

Contact Dermatitis in Construction Workers in Northeastern Italian Patch Test Database Between 1996 and 2016.

BACKGROUND: Contact dermatitis in construction workers (CWs) is frequent due to the widespread exposure to sensitizing substances and irritating agents and the wet and cold working conditions. OBJECTIVE: Our objectives were to evaluate contact dermatitis characteristics among CWs who underwent patch test in northeastern Italy and to identify related allergens. METHODS: Seven hundred ninety-five CWs were studied and their data were compared to 2.099 male white-collar workers. The associations between patch test results and occupations were assessed by multivariate logistic regression analysis. Incidence data were calculated from 1996 to 2016. RESULTS: CWs with confirmed occupational dermatitis presented an increased risk to be sensitized to potassium dichromate [OR 3.1 (95%IC 2.0-4.8)], to thiurams [OR 8 .6 (95%IC 4.0-18.4)], and to epoxy resins [OR 12.7 (95%IC 6.1-26.4)]. Sensitization to chromate decreased significantly after 2004, following EU regulation of chromate content in concrete, while sensitization to epoxy resins and thiurams increased. The overall incidence of occupational contact dermatitis in CWs decreased significantly. CONCLUSION: Our study demonstrated the effectiveness of EU regulations in reducing chromate sensitization in CWs and the overall incidence of occupational contact dermatitis. However, sensitization to other haptens is increasing, though improvement of protective measures is compulsory.

Cytogenetic and molecular aberrations and worse outcome for male patients in systemic mastocytosis.

In systemic mastocytosis (SM), the clinical features and survival vary greatly. Patient-related factors determining the outcome in SM are largely unknown. Methods: We examined the impact of sex on the clinical features, progression-free survival (PFS), and overall survival (OS) in 3403 patients with mastocytosis collected in the registry of the European Competence Network on Mastocytosis (ECNM). The impact of cytogenetic and molecular genetic aberrations on sex differences was analyzed in a subset of patients. Results: Of all patients enrolled, 55.3% were females. However, a male predominance was found in a subset of advanced SM (AdvSM) patients, namely SM with an associated hematologic neoplasm (SM-AHN, 70%; p < 0.001). Correspondingly, organomegaly (male: 23% vs. female: 13%, p = 0.007) was more, whereas skin involvement (male: 71% vs. female: 86%, p = 0.001) was less frequent in males. In all patients together, OS (p < 0.0001) was significantly inferior in males, and also within the WHO sub-categories indolent SM, aggressive SM (ASM) and SM-AHN. PFS was significantly (p = 0.0002) worse in males when all patients were grouped together; due to low numbers of events, this significance persisted only in the subcategory smoldering SM. Finally, prognostically relevant cytogenetic abnormalities (10% vs. 5%, p = 0.006) or molecular aberrations (SRSF2/ASXL1/RUNX1 profile; 63% vs. 40%, p = 0.003) were more frequently present in males. Conclusions: Male sex has a major impact on clinical features, disease progression, and survival in mastocytosis. Male patients have an inferior survival, which seems related to the fact that they more frequently develop a multi-mutated AdvSM associated with a high-risk molecular background.

Formaldehyde 2% is not a useful means of detecting allergy to formaldehyde releasers- results of the ESSCA network, 2015-2018.

BACKGROUND: Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq. OBJECTIVES: To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS. MATERIALS AND METHODS: A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs. RESULTS: A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] -0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance. CONCLUSIONS: Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen.

Scoring the Risk of Having Systemic Mastocytosis in Adult Patients with Mastocytosis in the Skin.

BACKGROUND: Mastocytosis in adults often presents with skin lesions. A bone marrow biopsy is necessary to confirm or exclude the presence of systemic mastocytosis (SM) in these cases. When a bone marrow biopsy is not performed, the provisional diagnosis is mastocytosis in the skin (MIS). No generally accepted scoring system has been established to estimate the risk of SM in these patients. OBJECTIVE: To develop a risk score to predict SM in adults with MIS. METHODS: We examined 1145 patients with MIS from the European Competence Network on Mastocytosis Registry who underwent a bone marrow biopsy. A total of 944 patients had SM and 201 patients had cutaneous mastocytosis; 63.7% were female, and 36.3% were male. Median age was 44 ± 13.3 years. The median serum tryptase level amounted to 29.3 ± 81.9 ng/mL. We established a multivariate regression model using the whole population of patients as a training and validation set (bootstrapping). A risk score was developed and validated with receiver-operating curves. RESULTS: In the multivariate model, the tryptase level (P < .001), constitutional/cardiovascular symptoms (P = .014), and bone symptoms/osteoporosis (P < .001) were independent predictors of SM (P < .001; sensitivity, 90.7%; specificity, 69.1%). A 6-point risk score was established (risk, 10.7%-98.0%) and validated. CONCLUSIONS: Using a large data set of the European Competence Network on Mastocytosis Registry, we created a risk score to predict the presence of SM in patients with MIS. Although the score will need further validation in independent cohorts, our score seems to discriminate safely between patients with SM and with pure cutaneous mastocytosis.