Update on Mastocytosis (Part 2): Categories, Prognosis, and Treatment

Systemic mastocytosis successfully managed using CytoSorb® during cardiopulmonary bypass for aortic valve replacement

ABSTRACT

We describe the case of a 72-year-old male with a history of systemic mastocytosis scheduled for on-pump aortic valve replacement for severe aortic insufficiency. Anesthesia and peri-operative management included avoidance of histamine-releasing drugs, methylprednisolone and clemastin prophylaxis. Furthermore, a CytoSorb® cartridge has been added to the bypass circuit and hemoadsorption was performed throughout the entire cardiopulmonary bypass (CPB) duration. CytoSorb® is a hemoadsorption device designed to remove various cytokines and drugs from the blood. The use of CytoSorb® during CPB in our case was not associated with adverse events, and the patient did not present any allergic or anaphylactic reaction.

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.

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.

Feline maculopapular cutaneous mastocytosis: a retrospective study of 13 cases and proposal for a new classification

CASE SERIES SUMMARY

Cutaneous mastocytosis is a disorder rarely reported in veterinary dermatology and usually described as 'urticaria pigmentosa'. This study aimed to evaluate the diagnosis, treatment and outcome of 13 affected cats, selected from the files of a private referral dermatology practice within a period of 14 years. Breeds of the affected individuals included Sphynx (n = 9), Devon Rex (n = 2) and Sphynx/Devon Rex crossbreeds (n = 2). Females (n = 9) were over-represented and the median duration of clinical signs prior to diagnosis was 8 months. The clinical presentation of these 13 cats was compared with cases reported in the veterinary literature and classified according to the current human consensus on cutaneous mastocytosis. Three clinical forms could be distinguished in cats: (1) large papular lesions and wheals, typically localised to the head, shoulders, ventral neck and axillae, and which may spontaneously resolve (termed polymorphic maculopapular cutaneous mastocytosis); (2) erythematous dermatitis, characterised by small maculopapular lesions often associated with crusts and with a poorer prognosis (termed monomorphic maculopapular cutaneous mastocytosis); and (3) more chronic dermatitis characterised by lichenification and hyperpigmentation, similar to the human condition 'urticaria pigmentosa' (termed pigmented maculopapular cutaneous mastocytosis). Histopathology was performed in eight cases and revealed a superficial-to-deep dermatitis characterised by infiltrates of mast cells and eosinophils. The response to various treatments, including antihistamines, steroids and ciclosporin, was variable.

RELEVANCE AND NOVEL INFORMATION

This article reports 13 new cases of feline cutaneous mastocytosis, confirming the clinical presentation and apparent breed predisposition. The feline maculopapular cutaneous mastocytosis seems to be clinically very close to the human form. This study proposes a new classification system for the feline disease based on the current human consensus, clinical presentation and prognosis, with three different subforms: polymorphic maculopapular cutaneous mastocytosis with eventual spontaneous regression; monomorphic maculopapular cutaneous mastocytosis with chronic evolution; and pigmented maculopapular cutaneous mastocytosis.

Childhood Solitary Cutaneous Mastocytoma: Clinical Manifestations, Diagnosis, Evaluation, and Management

BACKGROUND

The diagnosis of solitary cutaneous mastocytoma is mainly clinical, based on lesion morphology, the presence of a positive Darier sign, and the absence of systemic involvement. Knowledge of this condition is important so that an accurate diagnosis can be made.

OBJECTIVE

To familiarize physicians with the clinical manifestations, diagnosis, evaluation, and management of a solitary cutaneous mastocytoma.

METHODS

A PubMed search was completed in Clinical Queries using the key term "solitary cutaneous mastocytoma". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. Only papers published in English language were included. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Typically, a solitary cutaneous mastocytoma presents as an indurated, erythematous, yellow- brown or reddish-brown macule, papule, plaque or nodule, usually measuring up to 5 cm in diameter. The lesion often has a peau d'orange appearance and a leathery or rubbery consistency. A solitary cutaneous mastocytoma may urticate spontaneously or when stroked or rubbed (Darier sign). Organomegaly and lymphadenopathy are characteristically absent. The majority of patients with skin lesions that erupt within the first two years of life have spontaneous resolution of the lesions before puberty. Treatment is mainly symptomatic. Reassurance and avoidance of triggering factors suffice in most cases.

CONCLUSION

The diagnosis is mainly clinical, based on the morphology of the lesion, the presence of a positive Darier sign, and the absence of systemic involvement. A skin biopsy is usually not necessary unless the diagnosis is in doubt.

Dermatoscopy of Common Lesions in Pediatric Dermatology

The use of dermatoscopy to assist in the diagnosis of a variety of proliferative, pigmentary, inflammatory, infectious, congenital, and genetic cutaneous and skin appendage disorders is constantly increasing, as it is effective, affordable, noninvasive, and quick to perform.

Cutaneous mastocytosis treatment: strategies, limitations and perspectives

Mastocytosis is a rare myeloproliferative disease, characterized by excessive proliferation and accumulation of mast cells in the tissues. In cutaneous mastocytosis (CM), mast cells infiltration is limited to the skin, whereas in systemic mastocytosis (SM) internal organs are involved. The first-line treatment in CM is antimediator therapy (mainly H1 and H2 antihistamines) and short-term topical corticosteroids. Phototherapy is the second-line therapy which may be considered when antihistamines do not produce the expected improvement. New therapeutic options include omalizumab and KIT-targeting agents. Although the disappearance of skin lesions has been reported as a result of cytoreductive therapies in SM, the use of potentially toxic drugs in CM is not recommended. In all adults with mastocytosis and in pediatric patients with severe CM, a persistently elevated serum tryptase level and anaphylaxis in medical history, equipping with epinephrine autoinjector for use in case of anaphylaxis is recommended.

Granular IgM Deposition at Basement Membrane Zone in an Infant with Diffuse Cutaneous Mastocytosis

Diffuse Cutaneous mastocytosis (DCM) occurs due to abnormal accumulation of mast cells in the skin. We report an 8-month-old infant presented papulovesicular lesions, predominantly on the trunk. Skin biopsy revealed subepidermal bulla, interspersed with mast cells, eosinophils and neutrophils. Direct immunofluorescence microscopy of perilesional skin revealed nonspecific deposition of IgM in granular pattern along the dermoepidermal junction.