Indolent systemic mastocytosis treated with narrow-band UVB phototherapy: study of five cases

Mastocytosis - pathogenesis, clinical manifestation and treatment

The term mastocytosis designates a group of rare disorders characterized by typical skin lesions, frequently associated episodes of anaphylaxis, and clinical symptoms related to the release of various mediators. Dermatologists/allergists are frequently the first to establish the diagnosis. The condition is based on clonal mast cell proliferation, usually in the skin or bone marrow and only rarely in the gastrointestinal tract or other tissues. In general, mastocytosis has a good prognosis in terms of life expectancy. Rare variants - including mast cell leukemia, aggressive mastocytosis, and the exceedingly rare mast cell sarcoma - require cytoreductive therapy. In cases associated with hematological neoplasms, the prognosis depends on the underlying hematologic disorder.

Ultraviolet radiation and skin mast cells: Effects, mechanisms and relevance for skin diseases

Mast cells (MCs) are well known as versatile effector cells in allergic reactions and several other immune responses. Skin MCs and cutaneous MC responses are subject to the effects of environmental factors including ultraviolet radiation (UVR). Numerous studies have assessed the effects of UVR on MCs, in vitro and in vivo. Interestingly, UVR seems to have variable effects on non-activated and activated mast cells. In general, UV therapy is beneficial in the treatment of urticaria and mastocytosis, but the effects are variable depending on treatment regimen and type of UVR. Here, we review and summarise key reports from the older and current literature on the crosstalk of UVR and skin MCs. Specifically, we present the literature and discuss published reports on the effects of UVR on skin MCs in rodents and humans. In addition, we review the role of MCs in UVR-driven skin diseases and the influence of UV light on MC-mediated skin diseases. This summary of our current understanding of the interplay of skin MCs and UVR may help to improve the management of patients with urticaria and other MC disorders, to identify current gaps of knowledge, and to guide further research.

Advances in the understanding and clinical management of mastocytosis and clonal mast cell activation syndromes

Clonal mast cell activation syndromes and indolent systemic mastocytosis without skin involvement are two emerging entities that sometimes might be clinically difficult to distinguish, and they involve a great challenge for the physician from both a diagnostic and a therapeutic point of view. Furthermore, final diagnosis of both entities requires a bone marrow study; it is recommended that this be done in reference centers. In this article, we address the current consensus and guidelines for the suspicion, diagnosis, classification, treatment, and management of these two entities.

Risk of solid cancer, cardiovascular disease, anaphylaxis, osteoporosis and fractures in patients with systemic mastocytosis: A nationwide population-based study

In patients with systemic mastocytosis (SM), several aspects of morbidity remain poorly understood. We assessed the risk of solid cancers, cardiovascular disease, anaphylaxis, osteoporosis, and fractures in SM patients. Using Danish medical registries, we conducted a nationwide population-based cohort study including 687 adult (≥15 years) SM patients diagnosed during 1997-2012. A comparison cohort of 68,700 subjects from the general Danish population who were alive and without SM at the given SM subject's diagnosis were age- and gender-matched. Outcomes were a new diagnosis of solid cancer, venous thromboembolism (VTE), myocardial infarction (MI), stroke, anaphylaxis, osteoporosis, or fracture. For solid cancers the hazard ratio (HR) was 2.4 (95% confidence interval [CI] 1.9-2.8) with a 10-year absolute risk (AR) in the SM-cohort of 12.6% (95% CI 9.4-16.3). Specifically, we found a HR of 7.5 (95% CI 4.4-13.0) for melanoma and a HR of 2.5 (95% CI 1.7-3.5) for non-melanoma skin cancers (NMSCs). For VTE we found a HR of 1.9 (95% CI 1.2-3.0), with a 10-year AR of 3.9% (95% CI 2.3-6.1); for MI a nonsignificant increased HR of 1.4 (95% CI 0.9-2.3), with a 10-year AR of 1.8% (95% CI 0.9-3.2); and for stroke a HR of 1.6 (95% CI 1.1-2.3) with a 10-year AR of 4.6% (95% CI 2.8-6.9). The HR for anaphylaxis was 7.2 (95% CI 5.3-9.9), and the 10-year AR was 3.1% (95% CI 1.9-4.9). For osteoporosis the HR was 3.6 (95% CI 2.7-4.6) with a 10-year AR of 7.2% (95% CI 5.2-9.8). For fractures the HR was 1.2 (95% CI 0.9-1.6) and the 10-year AR was 5.9% (95% CI 3.9-8.4). SM patients are at increased risk of solid cancers - especially melanoma and NMSC-and cardiovascular disease. The risk of anaphylaxis and osteoporosis is clearly increased in SM, though absolute risk was low in this population-based study. The fracture-risk was only slightly increased. Am. J. Hematol. 91:1069-1075, 2016. © 2016 Wiley Periodicals, Inc.

Narrow-band UVB phototherapy and psoralen-ultraviolet A photochemotherapy in the treatment of cutaneous mastocytosis: a study in 20 patients

BACKGROUND

In mastocytosis, the skin is almost invariably involved, and cutaneous symptoms deeply affect patients' quality of life.

METHODS

A retrospective observational analysis of patients affected by cutaneous mastocytosis (CM) and indolent systemic mastocytosis (ISM) treated with phototherapy/photochemotherapy (PUVA or NB-UVB) has been conducted. For each patient, total numbers of PUVA or NB-UVB exposures, the cumulative UV dose (J/cm² ), serum tryptase profile, and pruritus, before and after treatment, according to the visual analogue scale (VAS) were considered. Skin lesions of each patient were assessed, before and after treatment, according to a cutaneous scale score.

RESULTS

Twenty patients affected by CM and ISM were studied; in particular, 10 patients received NB-UVB therapy, and other 10 patients received PUVA. A statistically significant mean reduction of pruritus in both groups (P < 0.01) was observed. The number of treatments necessary to obtain symptom relief was significantly lower in the PUVA group, but the mean exposure dose was significantly higher, if compared to the NB-UVB group. Serum tryptase levels showed a downward trend. The cutaneous score improved in both groups.

LIMITATIONS

This study was a retrospective study with a small sample size and without a control group.

CONCLUSION

This work provides evidence that both NB-UVB and PUVA represent a safe and useful second-line therapy of the cutaneous symptoms in mastocytosis.

Phototherapy for alopecia areata

Phototherapy is a useful therapeutic method for various skin diseases due to its modulatory effect on the cutaneous immune system. Alopecia areata is a dermatosis characterized by partial or complete hair loss. Collapse of the immune privilege of the hair follicle, which induces noncicatricial alopecia, is an important factor in its etiology. Several forms of phototherapy are used in dermatology.

The EAACI/GA(2) LEN/EDF/WAO Guideline for the definition, classification, diagnosis, and management of urticaria: the 2013 revision and update

This guideline is the result of a systematic literature review using the 'Grading of Recommendations Assessment, Development and Evaluation' (GRADE) methodology and a structured consensus conference held on 28 and 29 November 2012, in Berlin. It is a joint initiative of the Dermatology Section of the European Academy of Allergy and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2) LEN), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO) with the participation of delegates of 21 national and international societies. Urticaria is a frequent, mast cell-driven disease, presenting with wheals, angioedema, or both. The life-time prevalence for acute urticaria is approximately 20%. Chronic spontaneous urticaria and other chronic forms of urticaria do not only cause a decrease in quality of life, but also affect performance at work and school and, as such, are members of the group of severe allergic diseases. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors and pathomechanisms. In addition, it outlines evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

A 1-year-old boy with persistent, generalized eruption. Urticaria pigmentosa

A healthy 1-year-old boy born at full term after an uncomplicated pregnancy presented to the dermatology clinic for a widespread eruption with gradual onset since 3 months of age. He was otherwise well, afebrile, feeding well, and gaining weight appropriately. The child was overall asymptomatic, though some of his lesions occasionally became red and pruritic. His mother noticed that after mild illnesses, he was more prone to these flares. She denied flushing, vomiting, diarrhea, respiratory distress, and irritability. He was meeting all developmental milestones and started walking at 11 months of age. The remainder of his review of systems was unremarkable, and family history was noncontributory. Physical exam revealed a well-appearing, well-nourished, playful, and interactive toddler. There were innumerable discrete and coalescing pink-brown macules and papules concentrated on the trunk and extending onto the proximal upper and lower extremities bilaterally, as well as the neck and lower face. Stroking the lesions quickly led to development of erythematous edematous wheals. There was no hepatosplenomegaly, and the lymph node exam was unremarkable.

Clonal mast cell proliferation in pruriginous skin in hypereosinophilic syndrome

BACKGROUND

Hypereosinophilic syndrome (HES) is defined as a high eosinophilic granulocyte count in peripheral blood and other tissues. It can be associated with clonal and non-clonal haematological neoplastic diseases.

METHODS

Here we present a patient with a 27-year history of pruritus, urticarial lesions, recurrent diarrhoea, depression and a monoclonal gammopathy in the setting of HES.

RESULTS

The patient presented with erythemas, disseminated plaques, papules and scaling. Eosinophils continuously increased from 14% in 2002 to 65% in 2011. Tryptase levels were >20 µg/l. Skin biopsies were unspecific. In the bone marrow biopsy 30% of eosinophilic differentiated precursors and 10% plasma cells were noticed. Skin and bone marrow initially not indicative for mast cell proliferation were investigated for clonal mast cell proliferation. By immunostaining, single tryptase-, CD117c- and CD25-positive mast cells were detected not only in bone marrow, but also in the skin. Molecular investigations revealed a D816V exon 17 mutation of the c-KIT gene in bone marrow and skin biopsies.

CONCLUSION

In this patient HES was associated with high tryptase levels with 2 underlying clonal cell populations - IgGκ-positive plasma cells and single clonal mast cells with a high percentage of eosinophils in the bone marrow with symptoms of a clonal mast cell activation syndrome. Because of 3 minor criteria the patient finally fulfilled the criteria for systemic mastocytosis (according to the WHO). Patients with high tryptase levels and symptoms of mast cell activation syndrome should be investigated for clonal mast cell disease even in the absence of increased mast cells in the skin and bone marrow.