Cutaneous mastocytosis in children: a clinical analysis of 71 cases

OBJECTIVE: To characterize the clinical features, response to therapy, evolution and prognosis of cutaneous mastocytosis in children. BACKGROUND: Mastocytosis in children, instead of being induced by a potentially oncogenic c-kit mutation, is probably a clonal disease with benign prognosis. METHODS: The clinicopathological features, evolution and response to treatment were analysed in 71 children with mastocytosis. RESULTS: There were 53 (75%) cases of urticaria pigmentosa, 12 (17%) cases of mastocytoma, and six (8%) cases of diffuse cutaneous mastocytosis. In 92% of cases disease onset was in the first year of life. There was a male predominance 1.8 : 1. Treatment did not modify the disease evolution. Eighty per cent of patients improved or had spontaneous resolution of the disease. CONCLUSION: The most frequent clinical form of mastocytosis was urticaria pigmentosa followed by mastocytoma and diffuse cutaneous mastocytosis. Darier's sign was present in 94% of cases. A negative Darier's sign does not rule out mastocytosis. In contrast to adults, mastocytosis in children usually has a benign course making sophisticated or invasive diagnostic tests unnecessary. A classification of paediatric cutaneous mastocytosis is proposed.     

Cutaneous mastocytosis: demographic aspects and clinical features of 55 patients

BACKGROUND: Mastocytosis is a rare, heterogeneous group of disorder with abnormal increase of mast cells in one or more organ systems. OBJECTIVE: To evaluate the demographic and clinical features of cutaneous mastocytosis (CM). METHODS: Records of 55 patients with cutaneous mastocytosis were retrospectively analysed. RESULTS: Of the 22 females and 33 males, 80% had urticaria pigmentosa/maculopapular CM and 20% had mastocytoma. Of all cases, 81.8% had first lesions in childhood. The most common presentation was involvement of trunk together with extremities. Thirteen (23.6%) patients had history of bulla; Darier's sign was positive in 34 of 38 patients. Itching was the most common complaint, provocated by hot weather/bath. CONCLUSION: Clinical presentations of urticaria pigmentosa/maculopapular CM and mastocytoma are similar regarding gender, age of onset, age of diagnosis, and presence of Darier's sign and history of bulla. In contrast to mastocytoma, urticaria pigmentosa/maculopapular CM lesions were frequently located on trunk together with extremities.     

183例儿童皮肤型肥大细胞增生症临床及预后分析

目的 探讨儿童皮肤型肥大细胞增生症的临床特征及预后。 方法 回顾分析183例儿童皮肤型肥大细胞增生症患者的临床资料,并随访部分患者。 结果 183例患者中,色素性荨麻疹136例（74.3%）,肥大细胞瘤43例（23.5%）,弥漫性肥大细胞增生症4例（2.2%）;生后2岁内发病者179例（97.8%）。43例肥大细胞瘤患者中出生即发病者21例（48.8%）,出生后至6个月发病者17例（39.5%）,136例色素性荨麻疹患者中出生即发病者35例（25.7%）,出生至6个月发病者78例（57.3%）。伴随症状记录详细的33例患者中,10例出现伴随症状,其中9例为潮红发作。对45例患者随访3 ~ 6年（平均4年）,色素性荨麻疹患者1例于11岁时皮损完全消退,18例皮损部分消退;肥大细胞瘤患者1例皮损于8岁时完全消退,7例行皮肤活检后1年内皮损消退。口服抗组胺药可控制患者潮红、风团及水疱等症状;口服糖皮质激素可有效控制弥漫性肥大细胞增生症患儿反复发生的泛发水疱、大疱。 结论 儿童皮肤型肥大细胞增生症以色素性荨麻疹最常见,其次为肥大细胞瘤。肥大细胞瘤多于出生即发病,而色素性荨麻疹以出生后至6个月发病多见。口服抗组胺药可控制介质释放相关症状。严重的弥漫性肥大细胞增生症患者可口服糖皮质激素控制症状。     

Cutaneous mastocytosis: A dermatological perspective

Mastocytosis is a rare disease characterised by expansion and collection of clonal mast cells in various organs including the skin, bone marrow, spleen, lymph nodes and gastrointestinal tract. The prevalence of mastocytosis has been estimated to be one in 10 000, while the estimated incidence is one per 100 000 people per year. Cutaneous mastocytosis is classified into (i) maculopapular cutaneous mastocytosis, also known as urticaria pigmentosa; (ii) diffuse cutaneous mastocytosis; and (iii) mastocytoma of the skin. In adults, cutaneous lesions are usually associated with indolent systemic mastocytosis and have a chronic evolution. Paediatric patients, on the contrary, have often cutaneous manifestations without systemic involvement and usually experience a spontaneous regression. Diagnosis of cutaneous mastocytosis may be challenging due to the rarity of the disease and the overlap of cutaneous manifestations. This short review describes pathogenesis and clinical aspects of cutaneous mastocytosis with a focus on diagnosis and currently available therapies.     

Cutaneous mastocytosis in twins: multiple mastocytomas and urticaria pigmentosa in two pairs of monozygotic twins

We report two sets of monozygotic twins with cutaneous mastocytosis: one set with urticaria pigmentosa and the other set with multiple mastocytomas. This is the first report of multiple mastocytomas in twins to our knowledge.     

Evidence for altered mast cell proliferation and apoptosis in cutaneous mastocytosis

BACKGROUND: Mastocytosis presents as a focal or generalized increase of mast cells, particularly in the skin, but also in other organs. Activating mutations of KIT (formerly c-kit), the receptor of the mast cell growth factor stem cell factor (SCF), appear to play a key role in the pathogenesis of sporadic adult onset mastocytosis. However, these mutations are not present in childhood-onset and familial mastocytosis and also fail to explain the heterogeneity of adult-onset disease. Other factors such as prolonged survival of mast cells may therefore participate in causing and modulating the pathological increase of mast cells in mastocytosis. OBJECTIVES: To examine the expression of proliferation and apoptosis markers in the mast cells of cutaneous mastocytosis lesions in order to gain further insight into the pathogenesis of mastocytosis. METHODS: Lesional cutaneous biopsies from eight infants with solitary mastocytomas, five children with multiple mastocytomas, 11 children with generalized urticaria pigmentosa, 12 adults with urticaria pigmentosa, and skin from seven normal controls were used in this study. Serial sections were stained with toluidine blue to quantify mast cell numbers and with antibodies against the proliferation marker Ki67 protein, the tumour suppressor protein p53, and the inhibitor of cyclins and cyclin-dependent kinases p21WAF1/CIP1, using the alkaline phosphatase antialkaline phosphatase technique. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method was used to assess apoptosis. RESULTS: Cutaneous mast cell counts were significantly increased in all patient sections, particularly in childhood lesions, and similarly, a small but significant increase of proliferation was found in the lesional mast cells of all patients. Enhanced mast cell numbers and proliferation was associated with a significant decrease of TUNEL staining, particularly in mastocytomas. p53 expression was highly variable, with an overall significant increase in all patient skin mast cells, whereas p21 expression was barely observed at all. CONCLUSIONS: These findings further support the concept that an imbalance of mast cell proliferation and apoptosis is prevalent in mastocytosis lesions that may account in part for the increased focal mast cell accumulation in this condition.     

Diffuse cutaneous bullous mastocytosis with IgM deposits at dermo–epidermal junction

Cutaneous mastocytosis is a disease characterized by the infiltration and proliferation of mast cells in the skin. In children, the most common form of presentation is urticaria pigmentosa, while the diffuse cutaneous bullous mastocytosis is one of the rarest subtypes seen. The aim of this paper is to present a case of diffuse bullous mastocytosis with detection of IgM deposits at dermo–epidermal junction using direct immunofluorescence (DIF) microscopy. The diagnosis of diffuse bullous mastocytosis is a challenge, and DIF microscopy is necessary in order to exclude an autoimmune bullous disorder. However, IgM deposits at dermo–epidermal junction can be nonspecific, being found in a variety of skin disorders. A 6‐month‐old girl presented with bullous lesions and erosions on the scalp and the trunk. During hospitalization, further bullous lesions appeared, along with generalized erythrodermia. Skin biopsy revealed aspects of urticaria pigmentosa. Taking into account the clinical findings, the case was enclosed as bullous mastocytosis. Treatment included the avoidance of trigger factors, and administration of antihistamines along with a short‐term course of systemic steroids. The evolution was favorable, with remission of the existing lesions and without occurrence of new ones.     

皮肤肥大细胞增生症15例临床病理分析

目的:探讨皮肤肥大细胞增生症(CM)的临床病理和免疫表型特征.方法:对15例CM进行临床病理观察和免疫表型检测(SP法染色).结果:15例患者年龄为2个月～27岁,其中10例患者年龄<6个月,男:女为1:1.1.荨麻疹样色素沉着/斑丘疹皮肤肥大细胞增生症13例,肥大细胞瘤2例.甲苯胺蓝染色显示15例肥大细胞胞质内均出现多少不等的紫红色异染颗粒.免疫组化染色显示10/12例患者肥大细胞表达类胰蛋白酶(tryptase),8/12例患者肥大细胞表达CD117,所有患者肥大细胞均不表达CD1a和S-100蛋白.结论:CM好发于儿童,大多数患儿在6个月内发病,其诊断通过询问病史及体格检查可以确定,皮损组织病理检查可确定真皮内肥大细胞数量增多,但类胰蛋白酶或CD117阴性不能排除该病的诊断.儿童CM预后较好,大多数患儿皮损在青春前期或青春期改善或消退.     

Coexistence of two types of clinical lesions in childhood-onset mastocytosis

The vast majority of mastocytosis appear in childhood, urticaria pigmentosa (UP) and mastocytomas being the most common types. Terms such as "xanthelasmoid mastocytosis", "pseudoxanthomatous mastocytosis" or "nodular mastocytosis" have been introduced in the literature to describe the presence of yellowish papular or nodular lesions. We describe two children with cutaneous mastocytosis showing yellowish lesions in combination with other skin lesions. A 10-year-old girl presented with asymptomatic lesions in her vulva at birth, and developed brownish macules on her trunk years after. An eight-year-old boy presented with multiple yellowish papular lesions on his trunk, neck and limbs coexisting with a few clinically anetodermic lesions. No systemic involvement was found and the skin biopsy confirmed a cutaneous mastocytosis in both cases. The two patients are currently asymptomatic and are being periodically followed up. Mastocytoses may show a variety of clinical lesions, sometimes leading to misdiagnosis. Although there are previous reports, involvement of the mucosae and secondary anetoderma are not common findings in cutaneous mastocytoses. We consider that cutaneous manifestations of mastocytoses compose a clinical spectrum, thus explaining the coexistence of different clinical lesions and the development of uncommon presentations.     

Familial urticaria pigmentosa associated with thrombocytosis as the initial symptom of systemic mastocytosis and Down''s syndrome

Most cases of urticaria pigmentosa are confined to the skin, but visceral involvement and/or haematological abnormalities have been observed. It is still a matter of debate whether all forms of mastocytosis are true neoplasias or reactive hyperplasias. Familial inheritance of urticaria pigmentosa is rare. We report on a fraternal set with urticaria pigmentosa as part of a systemic mastocytosis. The first patient additionally revealed persistent thrombocytosis and splenomegaly. His brother developed urticaria pigmentosa, intermittent diarrhoea, hepatomegaly and asthma bronchiale associated with trisomy 21 (Down's syndrome). The association of mastocytosis with thrombocytosis has seldom been described. In our patient it preceded the development of systemic mastocytosis. The association with Down's syndrome has not been reported until now.     

Pediatric mastocytosis.

The onset of mastocytosis occurs between birth and 2 years of age in approximately 55% of all cases; an additional 10% develop the disease before the age of 15 years. Mastocytosis in these age groups differs in many respects from mastocytosis that has its onset in adulthood. The typical presentation of pediatric-onset mastocytosis consists of cutaneous manifestations: either a solitary mastocytoma, urticaria pigmentosa, or, less commonly, diffuse cutaneous mastocytosis. Particularly in infants, bullous eruptions may occur. Mastocytosis in infants and children may involve internal organs, including the bone marrow and the gastrointestinal tract, although such manifestations appear to be less common in children than in adults. Plasma histamine levels may be elevated in pediatric-onset mastocytosis. Treatment usually involves the use of H1 and H2 antihistamines to control itching and to control the hypersecretion of gastric acid that may occur. The prognosis for children with mast cell disease is variable; approximately half of the children with urticaria pigmentosa may experience resolution of lesions and symptoms by adolescence.     

Mastocytosis in children: a protocol for management

Abstract:  Mastocytosis is characterized by an increased number of mast cells with an abnormal growth and accumulation in one or more organs. In most children mastocytosis is limited to the skin (cutaneous mastocytosis) and often transient as compared with that in adults in whom mastocytosis is usually progressive and systemic. Generally, we recognize three more common forms of cutaneous mastocytosis: maculopapulous mastocytosis (formerly urticaria pigmentosa), mastocytoma of skin, and diffuse cutaneous mastocytosis. Childhood mastocytosis can further be divided into cutaneous mastocytosis (nonpersisting and persisting) and systemic mastocytosis (extremely rare). An approach to management using a set protocol is described in table form. In most cases of mastocytosis, only yearly checkups are necessary and no treatment is required; preventive recommendations are warranted in those individuals with systemic disease and constitutional symptoms. Symptomatic therapy is advised in only a minority of cases. This article is meant as a guideline for physicians involved in the care of children with mastocytosis and their parents.     

Pseudoangiomatous xanthelasmoid mastocytosis: two case reports showing the hypervascularity of this rare variant of cutaneous mastocytosis

Xanthelasmoid mastocytosis or xanthelasmoidea is a rare clinical variant of cutaneous mastocytosis characterized by a yellow hue of the clinical lesions, which are often misdiagnosed as juvenile xanthogranuloma. We present two pediatric cases of xanthelasmoid mastocytosis presenting as isolated mastocytomas, which are notable histopathologically for their hypervascularity. This pseudoangiomatous variant of cutaneous mastocytosis is important for pathologists to have knowledge of, so that a diagnosis of a vascular tumor is not rendered accidentally. The yellow hue has previously been explained by the usual deep and solid dermal mast cell infiltrate. In the two presented cases, however, the mast cell infiltrate was sparse, and the yellow color cannot be related to infiltrate density. We believe that the hypervascularity is at least one factor in the production of clinical xanthelasmoid appearance, and we propose the term ‘pseudoangiomatous xanthelasmoid mastocytosis’ to properly describe this rare variant of cutaneous mastocytosis.     

Telangiectasia macularis eruptiva perstans,a form of cutaneous mastocytosis,associated with malignant melanoma

A 62‐year‐old obese woman presented with a malignant melanoma (Stage la). In addition, she had disseminated telangiectatic macules on both thighs. Intensive rubbing of lesions resulted in wheals. Biopsy revealed increased numbers of mast cells. We diagnosed telangiectasia macularis eruptiva perstans, a rare clinical form of adult maculopapular cutaneous mastocytosis, a group which also includes urticaria pigmentosa. No evidence was found for systemic involvement. Possible associations with malignant tumors and the possible role of c‐kit mutations both in development of melanoma and mastocytosis are discussed.     

Serum tryptase measured with B12 and G5 antibody-based immunoassays in mastocytosis patients and its relation to histamine turnover

Serum tryptase was measured with the B12 and G5 antibody-based immunoassays in 25 adult patients with mastocytosis and in 18 controls. Twelve patients had uncomplicated cutaneous mastocytosis (urticaria pigmentosa) and 13 had urticaria pigmentosa with systemic symptoms. Tryptase levels were compared with histamine turnover estimated as urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid. Elevated B12 tryptase levels (> 20 μg/L) were found in most mastocytosis patients, including five of eight patients with only cutaneous manifestations who had a low urinary histamine metabolite excretion. This indicated a higher sensitivity for diagnosing mild mastocytosis on the basis of levels of serum tryptase as opposed to urinary methylimidazoleacetic acid. However, the serum B12 tryptase assay could not differentiate between urticaria pigmentosa patients with and without systemic disease: the measurement of histamine metabolite excretion probably reflects the mast cell burden more accurately. Serum G5 tryptase levels were generally low in both controls and mastocytosis patients.     

Expression of stem cell factor in cutaneous mastocytosis

Stem cell factor has recently been identified as a potent growth factor for bone marrow stem cells, melanocytes and mast cells. In order to evaluate its possible role in human mastocytosis, skin lesions from 13 patients with urticaria pigmentosa and five patients with mastocytomas, and normal skin specimens from five healthy donors were studied by immunohistochemistry, using polyclonal and monoclonal (hkl-12) antibodies against stem cell factor, and a monoclonal antibody (YB5.B8) against its receptor, the c-kit proto-oncogene product. Stem cell factor expression was noted in all sections studied, with an equal distribution pattern for both antibodies, but a weaker intensity with the hkl-12 reagent. Cytoplasmic staining was noted in keratinocytes, Langerhans cells, sweat gland ductal lining cells, mast cells, endothelial cells and spindle-shaped dermal stromal cells. An intense, diffusely granular reaction pattern was noted in all cells, except for a sparse, coarsely granular pattern in mast cells and stromal cells. In urticaria pigmentosa, staining was weaker in keratinocytes, but more prominent in Langerhans cells. In all sections, toluidine blue-positive mast cells and TA 99-positive basal epidermal melanocytes were the only cells to react with the c-kit antibody. Mastocytomas and urticaria pigmentosa lesions thus exhibit different patterns of stem cell factor expression. However, a possible pathogenetic role of this factor in mastocytosis remains to be determined.     

Urticaria pigmentosa adultorum and systemic mastocytosis--diagnostic principles and therapeutic possibilities

We report on the clinical picture of urticaria pigmentosa adultorum and systemic mastocytosis. In four out of five patients, we proved systemic mastocytosis by means of a biopsy from the iliac crest, although these patients did not complain of systemic signs and symptoms. In all cases, the cutaneous changes and clinical symptoms could be improved by a four-week-heliotherapy in the North Sea summer climate; itching did not reappear but five months later. Heliotherapy is regarded as an useful alternative concerning the treatment of urticaria pigmentosa and cutaneous manifestation of systemic mastocytosis.     

Diffuse Cutaneous Mastocytosis with Generalized Bullae

We report on a 9-month-old female infant with multiple tense bullae and erosions covering the entire body, including the face, scalp, and trunk. The histopathological examination revealed sub-epidermal bullae with a dense dermal cellular infiltrate. The infiltrate was identified as a collection of mast cells using toluidine blue and Giemsa stains. The direct immunofluorscence was negative. A diagnosis of cutaneous diffuse mastocytosis with generalized bullae was made based on these clinical and histopathological findings. In cases with diffuse cutaneous mastocytosis with generalized bullae, systemic involvement is more frequent and more severe compared to other types of cutaneous mastocytosis. Some lethal outcomes have been reported. This is the first reported case of diffuse cutaneous mastocytosis in the Korean literature.     

Paediatric mastocytosis: a systematic review of 1747 cases

Paediatric mastocytosis was previously considered to be a benign and spontaneously regressing disease. However, this evolution is impossible to predict. To clarify the characteristics and course of paediatric mastocytosis, we performed a literature review of 1747 cases published between 1950 and April 2014. Lesions occurred before the age of 2 years in 90% of cases, and presented as urticaria pigmentosa (75% of cases), mastocytoma (20%) or diffuse cutaneous mastocytosis (5%). The male‐to‐female ratio was 1·4. KIT D816V mutation was detected in 34% of 215 tested patients. Clinical regression (complete or partial) occurred in 67% of cases and stabilization in 27%. However, the outcome was fatal in 2·9% of patients.     

Oral disodium cromoglycate in mastocytosis

Oral disodium cromoglycate was found useful for the treatment of gastrointestinal manifestations of mastocytosis in 2 patients with systemic disease. The urinary excretion of histamine in these 2 patients decreased following treatment. Oral disodium cromoglycate had no effect on cutaneous symptoms, either in these 2 patients nor in 2 other patients with urticaria pigmentosa without signs of systemic mastocytosis. In the latter 2 patients the urinary excretion of histamine was unaffected. Treatment was given for 4 to 6 weeks and the dose of disodium cromoglycate was 100 mg four times daily in the 3 adult patients and 100 mg three times daily in the fourth patient, an 8-year-old boy.