Topical pimecrolimus for paediatric cutaneous mastocytosis

Cutaneous mastocytosis in childhood

Mastocytoses are characterized by clonal proliferation of mast cells in various tissues. In childhood, cutaneous mastocytosis (CM) occurs almost exclusively. It is confined to the skin, and has a good prognosis. The most common form is the maculopapular cutaneous mastocytosis (MPCM), formerly called urticaria pigmentosa. A distinction is made between a monomorphic variant of MPCM with multiple small, roundish maculopapular skin lesions and the - more common - polymorphic variant with larger lesions of variable size. One quarter of CM diagnosed in childhood are mastocytomas, which often occur solitary or at multiple sites. The diffuse variant of CM (DCM), which affects 5% of children with CM, should be distinguished from these forms. Systemic mastocytoses (SM) with mast cell infiltrates in the bone marrow or other extracutaneous tissues, such as the gastrointestinal tract, occur predominantly in adults. The diagnosis of CM is usually made clinically: Manifestation in infancy, typical morphology and distribution, pathognomonic Darier sign. Basal serum tryptase is determined if DCM or systemic mastocytosis are to be diagnosed. Children with mastocytosis should be managed in a specialized outpatient clinic. For affected families, detailed information about the clinical picture including prognosis assessment is essential. Mast cell mediated symptoms are controlled by oral non-sedating antihistamines if needed.

Pediatric Mastocytosis: An Update

Mastocytosis is a rare clonal disorder characterized by excessive proliferation and accumulation of mast cells (MC) in various organs and tissues. Cutaneous mastocytosis (CM), the most common form in children, is defined when MC infiltration is limited to the skin. In adults, the most common form is systemic mastocytosis (SM), characterized by MC proliferation and accumulation in organs, such as bone marrow, lymph nodes, liver, and spleen.1 Genetic aberrations, mainly the KIT D816V mutation, play a crucial role in the pathogenesis of mastocytosis, enhancing MC survival and subsequent accumulation in organs and tissues.2,3 CM includes three forms: solitary mastocytoma, maculopapular cutaneous mastocytosis (MPCM), and diffuse cutaneous mastocytosis (DCM). In most children with CM, skin lesions regress spontaneously around puberty; unfortunately, it is not always a self-limiting disease.4 Even if SM occurs occasionally, all children with mastocytosis require planned follow-up over time. Children with mastocytosis often suffer from MC mediator-related symptoms, the most common of which is itching, often triggered by rubbing the lesions. Management of pediatric mastocytosis is mainly based on strict avoidance of triggers. Treatment with H1 and H2 histamine receptor blockers on demand and the availability of epinephrine auto-injectors for the patients to use in case of severe anaphylactic reactions are recommended.

The pathogenesis of melasma and implications for treatment

BACKGROUND

Melasma is a complex and poorly understood disorder, with high rates of treatment failure and recurrences.

OBJECTIVES

We aimed to review the current knowledge of the pathogenesis of melasma and apply this knowledge to clinical implications on relevant therapeutic interventions.

METHODS

A systematic PubMed search was performed using the search term "((melasma[Text Word]) OR facial melanosis[Text Word]) AND (pathogenesis OR causality[MeSH Terms])" for articles published between 1990 and 2020. Included articles were then evaluated by two authors and assessed for relevant pathomechanistic pathways, after which they were divided into groups with minimal overlap. We then reviewed current treatment modalities for melasma and divided them according to the involved pathomechanistic pathway.

RESULTS

A total of 309 search results were retrieved among which 76 relevant articles were identified and reviewed. Five main pathomechanisms observed in melasma were identified: (1) melanocyte inappropriate activation; (2) aggregation of melanin and melanosomes in dermis and epidermis; (3a) increased mast cell count and (3b) solar elastosis; (4) altered basement membrane; and (5) increased vascularization. Treatment modalities were then divided based on these five pathways and detailed in 6 relevant tables.

CONCLUSION

The pathophysiology of melasma is multifactorial, resulting in treatment resistance and high recurrence rates. This wide variety of pathomechanisms should ideally be addressed separately in the treatment regimen in order to maximize results.

Mediator-Related Symptoms and Anaphylaxis in Children with Mastocytosis

Mastocytosis is characterized by the pathological accumulation of mast cells (MC) in various organs. In these patients, MC may degranulate and thereby contribute to clinical symptoms, especially when a concomitant allergy is present. However, MC activation can not only be induced by high-affinity receptors for IgE, but also by anaphylatoxins, neuropeptides, IgG immune complexes, complement-components, drugs, products of bacteria or parasites, as well as physical factors such as heat, cold, vibration, stress, sun, or physical effort. Symptoms due to mediators released by activated MC may develop in adults suffering from systemic mastocytosis, but also evolve in children who usually have cutaneous mastocytosis (CM). Clinically, CM is otherwise characterized by typical brown, maculopapular skin lesions or mastocytoma associated with a positive Darier's sign. Pruritus and flushing are common and blistering may also be recorded, especially in diffuse CM (DCM). Pediatric patients with mastocytosis may also have gastrointestinal, respiratory, and neurologic complaints. Although anaphylaxis is not a typical finding, pediatric patients with massive skin involvement and high tryptase levels have a relatively high risk to develop anaphylaxis. This paper reviews MC mediator-related symptoms and anaphylaxis in children with mastocytosis, with special emphasis on risk factors, triggers, and management.

Molecular Background, Clinical Features and Management of Pediatric Mastocytosis: Status 2021

Pediatric mastocytosis is a heterogeneous disease characterized by accumulation of mast cells in the skin and less frequently in other organs. Somatic or germline mutations in the KIT proto-oncogene are detected in most patients. Cutaneous mastocytosis is the most common form of the disease in children. In the majority of cases, skin lesions regress spontaneously around puberty. However, in few patients, mastocytosis is not a self-limiting disease, but persists into adulthood and can show signs of systemic involvement, especially when skin lesions are small-sized and monomorphic. Children with mastocytosis often suffer from mast cell mediator-related symptoms. Severe hypersensitivity reactions can also occur, mostly in patients with extensive skin lesions and blistering. In a substantial number of these cases, the triggering factor of anaphylaxis remains unidentified. Management of pediatric mastocytosis is mainly based on strict avoidance of triggers, treatment with H1 and H2 histamine receptor blockers, and equipment of patients and their families with epinephrine auto-injectors for use in severe anaphylactic reactions. Advanced systemic mastocytosis occurs occasionally. All children with mastocytosis require follow-up examinations. A bone marrow investigation is performed when advanced systemic mastocytosis is suspected and has an impact on therapy or when cutaneous disease persists into adulthood.

Pediatric Mastocytosis: Recognition and Management

Mastocytosis is a heterogeneous group of disorders characterized by the accumulation of clonal mast cells in organs such as the skin and bone marrow. In contrast to adults, most affected children have only cutaneous involvement. This article reviews the molecular pathogenesis, skin findings, mast cell mediator-related symptoms, evaluation, and management of childhood-onset mastocytosis, noting differences from adult-onset disease. Current classification of cutaneous mastocytosis and the natural histories of different variants in pediatric patients are highlighted, with a focus on clinical manifestations with prognostic implications. A practical algorithm is provided to guide clinical assessment, laboratory and other investigations, and longitudinal monitoring, including recognition of hepatosplenomegaly as a marker of systemic disease and utilization of allele-specific quantitative PCR (ASqPCR) to detect KIT mutations in the peripheral blood. Updated information and consensus-based recommendations regarding possible triggers of mast-cell degranulation (e.g., physical, medications) are discussed, with an emphasis on patient-specific factors and avoiding excessive parental concern. Lastly, an individualized, stepwise approach to treatment of symptoms, skin-directed therapy, and potential use of kinase inhibitors for severe systemic disease is outlined.

Pediatric mastocytosis

PURPOSE OF REVIEW

The current article highlights recent developments in the field of pediatric cutaneous mastocytosis. Mastocytosis is a spectrum of conditions that range from fleetingly benign to aggressively malignant. Through recognizing the natural progression of disease, the role of biomarkers and mutational analysis, treatment and risk of triggers, physicians can confidently stage, counsel and manage patients with pediatric cutaneous mastocytosis.

RECENT FINDINGS

Many lesions of cutaneous mastocytosis are chronic with some resolving around the mid-teenage years. KIT mutations are found in the majority of pediatric cutaneous mastocytosis but are not correlated with prognosis. Serum tryptase levels may be elevated in pediatric cutaneous mastocytosis patients without systemic mastocytosis. Pimecrolimus, omalizumab and tyrosine kinase inhibitors are effective treatment options. The low risk of NSAIDs and vaccinations has been characterized and epinephrine autoinjectors are rarely utilized in the pediatric cutaneous mastocytosis patient.

SUMMARY

Pediatric cutaneous mastocytosis is a heterogeneous disease with good outcome overall. Organomegaly, elevated tryptase levels and the presence of KIT mutation in peripheral blood may aid in the decision to pursue bone marrow biopsy. The armamentarium of treatments has expanded and better understanding of the significance of triggers and vaccination safety allows the clinician to thoughtfully counsel and allay anxiety around pediatric cutaneous mastocytosis.

Efficiency of long-term high-dose intravenous ascorbic acid therapy in locally advanced basal cell carcinoma - a pilot study

Introduction

The anti-cancer properties of high-dose intravenous ascorbic acid have been demonstrated in various malignancies. In our recent study, we tested topically applied ascorbic acid to treat basal cell carcinoma (BCC), and achieved a good clinical response.

Aim

Based on these results, we decided to examine the efficacy and tolerability of high-dose intravenous ascorbic acid (IVA) for locally advanced BCC.

Material and methods

In this pilot study, patients diagnosed with locally advanced BCC who were not amenable to radiation, surgical or local therapy (no other treatment option was available at the time) received intravenous ascorbic acid (1–1.8 g/kg), in an outpatient setting, 1–3 times per week for a mean duration of 42 ±23.6 weeks. This therapy was generally well tolerated.

Results

Among 4 patients who had a total of 165 (mean: 41 ±51, range: 1–114) skin lesions, 3 patients achieved stable disease and one had progressive disease. There was substantial variability in individual tumor response to therapy. With the aid of two-photon microscopy and second harmonic generation imaging techniques, alterations in collagen structure were observed between tumor nests during IVA therapy.

Conclusions

Our results suggest that IVA is well tolerated in a small group of patients with extensive BCCs. However, in the era of smoothened (Smo) receptor inhibitors, it may only be considered as an adjuvant therapy in treatment-resistant cases.

Maculopapular Cutaneous Mastocytosis in a Six-month-old Boy Who Presented with Respiratory Distress

Mastocytosis is a diverse group of rare disorders characterized by mast cell proliferation and its aberrant accumulation within various organs including respiratory, gastrointestinal, genitourinary mucosa and most commonly the skin. The spectrum of presentations ranges from torpid disease (cutaneous mastocytosis) having normal life span with transient sign and symptoms to highly vigorous disease (systemic mastocytosis) and life-threatening malignant conditions. Prevalence of the disease in general population is unknown. It occurs in all races and there is no sex predilection. Peak incidence is during infancy and early childhood with second peak occurring in middle age. We report a case of maculopapular cutaneous mastocytosis (MCM) in a six-month-old male child who presented with respiratory distress. According to our literature search it is one of the least frequent cases reported in our country, Pakistan.