PUVA-treatment of urticaria pigmentosa

Mastocytosis in the Skin: Approach to Diagnosis, Evaluation, and Management in Adult and Pediatric Patients

Mastocytosis is characterized by the clonal infiltration and proliferation of neoplastic mast cells into target organs. Clinical features of mastocytosis are based in large part on dysregulated mast cell mediator release. Affected individuals may present with isolated skin involvement or multisystemic disease with a spectrum of symptoms including anaphylaxis, pathologic fractures, and chronic gastrointestinal, neurocognitive, musculoskeletal, and constitutional symptoms. The term "mastocytosis in the skin" refers to individuals with cutaneous infiltration and encompasses both localized and systemic forms of disease. Cutaneous involvement is further categorized into cutaneous mastocytoma, diffuse cutaneous mastocytosis, and maculopapular cutaneous mastocytosis based on morphology. In ~95% of patients with systemic mastocytosis, the disease is driven by the KIT D816V somatic variant. The aim of this clinical review is to highlight the diagnostic considerations, management complexities, and evolving treatment landscape that must be considered when evaluating a patient presenting with mastocytosis in their skin. Clinical manifestations, histopathology, and laboratory parameters are essential to diagnosis and determining the disease burden in those with known or suspected systemic mastocytosis. Once appropriately staged, both skin-directed therapy as well as novel systemic treatment options, including selective tyrosine kinase inhibitors, can be considered with the potential to improve patient outcomes.

Anetodermic mastocytosis: response to PUVA therapy

Mastocytosis is a group of disorders characterized by the accumulation of mast cells in different tissues and organs. The skin is the most frequently involved organ (90% of cases) where mastocytosis may show a heterogenic clinical expression. Anetodermic lesions are an unusual clinical presentation of mastocytosis. We report a case of anetodermic mastocytosis in a 26-year-old man, with sparse lesions and a benign course. PUVA therapy obtained excellent results in this case. Darier's sign should be investigated in patients with anetodermic lesions of unclear origin in order to exclude cutaneous mastocytosis.

Treatment of Systemic Mastocytosis

It is an exciting time in the treatment of systemic mastocytosis. Major advances in the past 2 decades have helped to define the molecular abnormalities associated with this disease and to delineate pathways involved in its pathogenesis. This has directly translated into the development of novel targeted therapies. These therapies hold great promise to patients and health care providers that a "cure" for systemic mastocytosis may someday be obtainable.

Therapeutic approach to selected neonatal eruptions

Management of numerous neonatal eruptions has been modified over the past 10 years. In this article, traditional and developing therapeutic insights are applied to both common and uncommon neonatal conditions.

Phototherapy and PUVA photochemotherapy in children

The use of phototherapy and photochemotherapy in children has been limited due to concerns over their long-term carcinogenic potential. Furthermore, the method of administration is disconcerting to some children, particularly as phototherapy treatment units are seldom rendered 'child-friendly'. Despite these reservations, ultra-violet therapies can be useful treatment options for children with selected dermatological conditions provided they are used under carefully controlled conditions.

Urticaria pigmentosa

Urticaria pigmentosa (UP), resulting from the accumulation of excessive numbers of mast cells in the skin, is the most common form of cutaneous mastocytosis. Observations highlight the diversity of this disease. Clonal expansion of early hematopoietic progenitor cells carrying activating mutations in KIT seems to be the basis of adult-onset UP. New pathogenetic findings are leading to the development of new diagnostic surrogate markers of disease and therapeutic approaches targeting neoplastic mast cells. Promising strategies may arise from an increased understanding about the cause of mastocytosis and the signaling pathways initiated by kit activation.

[Treatment of systemic mastocytosis]

BACKGROUND

Systemic mastocytosis is a rare disease, characterized by mast cells proliferation in various organs. Two types of clinical manifestations can be distinguished: those related to mast cells mediators release and those related to tumoral proliferation involving different organs, these later defining aggressive systemic mastocytosis. Until recently, treatment was mainly symptomatic, without anti tumoral effect.

RECENT FACTS

These last years, advances have been made in the understanding of the disease with the discovery of the c-kit oncogene mutation and the approach of the disease as a myeloproliferative disorder.

PERSPECTIVES

Based on experiences acquired in the treatment of this kind of disorders, evaluation of new therapeutics, such as cladribine or combination of interferon-alpha and cytarabine is in progress. At least, tyrosine kinase inhibitors, a new family of molecules, are able of inhibiting some types of the mutated c-kit protein and one of them, imatinib mesylate, has shown a great efficacy in the treatment of gastro intestinal stromal tumors (GIST) which also involves the c-kit mutation. By analogy, treatment of patients with c-kit susceptible mutation might be treated with this molecule.

Alternative treatments for severely affected patients with urticaria

A none sedating antihistamine is the treatment of choice for most patients with urticaria. There are, however, several occasions where alternative treatments are appropriate. In this paper these alternative treatments of various types of urticaria are discussed. The treatment of anaphylactic shock where urticaria often is the first sign is also discussed. In all types of urticaria it is important to work with the patient and try to eradicate the cause or inhibit the mediators giving the clinical signs.

Mastocytosis

Mastocytosis represents a heterogeneous group of clinical disorders resulting from the infiltration of mast cells in the skin and other organs. Although mastocytosis was first described over 130 years ago, the pathophysiologic mechanisms responsible for this disease have been identified only recently. This article discusses the salient clinical features of the disease, the mechanisms responsible for its development, and provides treatment approaches that have proven useful for managing patients with this disorder.

Treatment of mastocytosis: pharmacologic basis and current concepts

Mastocytosis is a rare, heterogeneous disorder characterized by a marked increase in mast cell density in various tissues. Mast cells from different human tissues are heterogeneous. So far, there is no cure for systemic mastocytosis. Conventional therapy is based on agents that antagonize mediators released from mast cells, drugs that inhibit the release of mediators and agents that modulate mast cell proliferation. This pharmacologic approach is satisfactory in the majority of patients with indolent mastocytosis. At the beginning of the new millennium, the therapy of severe forms of aggressive mastocytosis remains a challenge for students of this intriguing disorder.

Mastocytosis: recent advances in defining the disease

Mastocytosis is a rare disease characterized by a primary pathological increase in mast cells in different tissues, which may present in a variety of clinical patterns. Major advances have been made in recent years in the understanding of the pathogenesis of mastocytosis. This review is aimed at familiarizing dermatologists with these recent findings, and at exploring their possible implications for the diagnosis and treatment of the condition. The heterogeneous clinical presentation of mastocytosis is detailed with respect to the type of skin lesions, age at onset, family history, organ systems involved, associated haematological disorders and prognosis. Recent genetic findings also indicate different pathogenetic forms of mastocytosis, as adult patients and those with associated haematological diseases usually express activating mutations of the stem cell factor receptor c-kit, whereas most cases of childhood-onset and familial mastocytosis seem to lack these mutations. Despite the presence of c-kit mutations, patients with cutaneous lesions generally have a good prognosis, even when there is involvement of other organs. Some patients, particularly those with childhood-onset disease, experience spontaneous remission, mostly by puberty. c-kit mutations do not explain the initial cause of mastocytosis, and their prognostic significance is as yet unclarified, as is the pathogenesis in patients without the mutations. Furthermore, these novel findings have as yet not resulted in a more effective treatment of the cause of the disease, so that counselling, prevention of exposure to mast cell secretory stimuli, and symptomatic treatment remain the mainstays of current patient management.

Mastocytosis and the skin

The most frequent site of organ involvement in individuals with any form of mastocytosis is the skin. Cutaneous lesions include urticaria pigmentosa, mastocytoma, diffuse and erythematous cutaneous mastocytosis, and telangiectasia macularis eruptiva perstans. The major histologic feature is an increase in the number of mast cells in the dermis. Treatment depends on the type of skin lesions.

Treatment of systemic mast cell disorders

The heterogeneous nature of disease manifestations in mastocytosis requires the individualization of therapy to each patient's clinical presentation and prognosis. The mainstay of treatment for most categories of mastocytosis are H1 and H2 antihistamines with the addition of corticosteroids for more severe symptoms. This article presents a summary of treatment strategies for indolent and aggressive forms of mastocytosis along with a discussion of future therapeutic directions.

Diffuse cutaneous mastocytosis with bone marrow infiltration in a child: a case report

Mastocytosis encompasses a range of disorders characterized by overproliferation and accumulation of tissue mast cells. Mast cell disease is most commonly seen in the skin, but the skeleton, gastrointestinal tract, bone marrow, and central nervous system may also be involved. We present a 10-year-old boy with diffuse cutaneous mastocytosis characterized by disseminated papular, nodular, and infiltrated leathery lesions. The patient presented with chronic diarrhea and malnutrition. Laboratory studies were normal except for an elevated urinary 1-methylhistamine level. The bone marrow aspirate showed a dense mast cell infiltrate confirming systemic involvement.

Phototherapy and photochemotherapy: an update

Three types of phototherapy and 2 forms of photochemotherapy are now available for treatment of more than 40 diseases of the skin. Broadband ultraviolet B (UVB) phototherapy and oral psoralen photochemotherapy (PUVA) therapy are most widely available while there has been increased interest in topical PUVA therapy. Narrow-band UVB phototherapy and UVA-1 phototherapy offer potential for the future.

Southwestern Internal Medicine Conference: mastocytosis: developments during the past decade

Mastocytosis is a spectrum of disorders characterized by an aberrant proliferation of tissue mast cells. Although this disease process often affects the skin, it may involve multiple organs. The clinical disorder varies according to patient age, the clinical manifestations demonstrated, and the extent of the mast cell proliferative process. A myriad of clinical symptoms occur, and these may be localized to the organ system involved or may be systemic, depending on whether there is local or generalized mast cell mediator release. Diagnosis includes the demonstration of increased tissue mast cells in involved organs as well as increased levels of biochemical mediators. Patients with cutaneous involvement only have the best prognosis. Treatment is directed toward stabilizing mast cell mediator release and blocking the effects of those mediators generated.

The mast cell and mast cell disease

Mast cell disease or mastocytosis is a heterogeneous group of clinical disorders characterized by the proliferation and accumulation of mast cells in a variety of tissues, most often the skin. The signs and symptoms of mast cell disease are varied, dependent on the localization of mast cells in different organs and the local and systemic effects of mediators released from these cells. Although mast cell disease is most commonly identified in the skin, involvement of the skeletal, hematopoietic, gastrointestinal, cardiopulmonary, and central nervous systems may be seen. Clinical management of mastocytosis depends most heavily on knowledge of the diverse effects of mast cell mediators on various tissues and organs, the stimuli that can cause their release, and the different methods available for blocking the effects of these mediators.

Photochemotherapy beyond psoriasis

Photochemotherapy involves the therapeutic use of nonionizing radiation in combination with a photosensitizing chemical to trigger a photochemical reaction that mediates a beneficial effect. The successful introduction and widespread use of psoralen photochemotherapy (PUVA) in the management of psoriasis was the chief stimulus for recent interest in the therapeutic use of nonionizing radiation in various other dermatoses. This article discusses the expanding spectrum of diseases responding to PUVA therapy. More than 30 conditions such as atopic dermatitis, mycosis fungoides, vitiligo, the photodermatoses, chronic graft-versus-host disease, and granuloma annulare have been successfully treated with oral psoralen photochemotherapy. Various mechanisms of response to treatment are discussed including photoimmunologic effects, selective cytotoxicity, alterations of cell function, and stimulation of melanocytes. Finally, the limitations to the use of PUVA therapy are identified and its future use in other cutaneous and systemic diseases are discussed.

Protoporphyrin and long-wave ultraviolet light modulate metabolic events in rat peritoneal mast cells

We have previously shown that protoporphyrin (PP) plus long-wave ultraviolet light (UVA) has an inhibitory effect on the release of histamine from rat peritoneal mast cells in response to various stimuli, without compromising cell viability. In the present study, we observed that protoporphyrin at a noncytolytic dose (3 ng/ml) plus UVA irradiation (0.038 J/cm2) is also able to suppress prostaglandin D2 generation by rat peritoneal mast cells in response to calcium ionophore A23187, compound 48/80, or anti-IgE antibody by 64%, 92%, and 100%, respectively. Because of the participation of protein kinase C in stimulus-secretion coupling in mast cells, we also investigated the effect of PP plus UVA on the release of histamine induced by the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA). PP plus UVA inhibited histamine release induced by PMA. The release of histamine induced by the synergistic combination of PMA (50 nM) and a low dose of calcium ionophore A23187 (0.1 microM) was also inhibited. PP plus UVA inhibited the release of histamine induced by the non-fluorescent calcium ionophore, 4-Br-A23187, by 47.8%, but had essentially no effect on changes in intracellular calcium induced by this stimulus. In contrast, both the release of histamine and changes in intracellular calcium stimulated by compound 48/80 were inhibited. We conclude from these results that PP plus UVA may affect both early and late biochemical events involved in mast cell mediator release.

Modulation of human cutaneous mast cell responsiveness by a single, low-dose, PUVA treatment

The present study was conducted to investigate whether a single administration of a relatively low dose of 8-methoxypsoralen (8-MP) with long-wave ultraviolet A (UVA) irradiation alters human skin test responses to a mast cell secretagogue, codeine, and to a vasodilator, histamine. Administration of 8-MP at a dose of 10 mg followed by UVA irradiation (1 joule/cm2) suppressed the skin flare-and-wheal response to codeine and decreased the number of visible degranulated mast cells in biopsy specimens examined histologically. UVA irradiation alone enhanced the skin wheal-and-flare response to either codeine or histamine. The inhibitory effect of 8-MP plus UVA irradiation on both wheal-and-flare responses to codeine tended to decrease, and an increasing enhancement of the skin response to histamine could be observed as the dose of 8-MP was increased from 10 to 30 mg. We postulate that (1) a single 8-MP plus UVA irradiation treatment at appropriate doses could be a potential approach to modulate the mediator-releasing properties of mast cells resident in the skin and (2) the underlying mechanisms of this inhibition is complex, probably reflecting a balance between the inhibitory effect of 8-MP plus UVA irradiation on mast cell-mediator release, enhancement of the vascular response to histamine, and direct photoactivation of resident mast cells.

The Skin in Mastocytosis

The most frequent site of organ involvement in patients with any form of mastocytosis is the skin. Cutaneous expressions include urticaria pigmentosa, mastocytoma, diffuse and erythrodermic cutaneous mastocytosis, and telangiectasia macularis eruptiva perstans. The cutaneous lesions tend to appear early in life. Although urticaria pigmentosa has been reported in 12 pairs of twins and one set of triplets, the majority of affected individuals have no familial association. Most patients with systemic mastocytosis have skin lesions; however, an occasional patient will have systemic disease with no other skin features than flushing. In lesional cutaneous sites and in non-lesional skin, there is an increase in the number of mast cells. Electron microscopy shows quantitative differences between lesional skin mast cells from patients with and without systemic disease. The mast cells from adult patients with systemic disease have a larger mean cytoplasmic area, nuclear size, and granule diameter. The granules contain predominantly grating/lattice structures. The cutaneous mast cells contain tryptase and chymase. They retain their functional reactivities to relevant secretory stimuli, such as C3a, morphine sulfate, and calcium ionophore A23187. Lesional skin contains histamine, leukotriene B4, prostaglandin D2, 5-hydroxyeicosatetraenoic acid, platelet-activating factor, and heparin. Treatment of the cutaneous manifestations includes the use of H1 and H2 antihistamines, oral disodium cromoglycate, psoralens plus ultraviolet A photochemotherapy, and potent topical corticosteroid preparations.

Photochemotherapy of dominant, diffuse, cutaneous mastocytosis

Diffuse, cutaneous mastocytosis is a rare variant of cutaneous mast cell infiltration that can arise in neonates or infants as a generalized bullous eruption. The mode of transmission is suggested as autosomal dominant. We report four infants from two unrelated families with diffuse cutaneous mastocytosis whose cutaneous disease was not controlled by initial therapies. Treatment of the four infants with photochemotherapy dramatically reduced or eliminated symptoms. One course of therapy resulted in improvement, and retreatment has not been required two to six years later.

Administration of 8-methoxypsoralen and ultraviolet A irradiation (PUVA) induces turnover of mast cells in the skin of C57BL/6 mice

Administration of 8-methoxypsoralen followed by ultraviolet A irradiation (PUVA treatment) has been used as a therapy for urticaria pigmentosa. The effect of PUVA treatment on cutaneous mast cells in mice was investigated by using giant granules of mast cells from C57BL/6-bgJ/bgJ (Chediak-Higashi syndrome) mice as a marker. C57BL/6-(+)/+ mice were lethally irradiated and rescued by bone marrow transplantation from C57BL/6-bgJ/bgJ mice. In the radiation chimeras, mast cells in the skin were of +/+ type and mast-cell precursors migrating in the bloodstream were bgJ/bgJ. When PUVA treatment was applied to the skin of the radiation chimeras, the total number of mast cells continued to decrease until the third week after the treatment and then recovered to pre-treatment levels. The initial reduction was attributed to the decrease of +/(+)-type mast cells, and the subsequent recovery to be as a result of the increase of bgJ/bgJ-type mast cells. This observation may explain the fact that the therapeutic effect of PUVA treatment is transient. Symptoms of urticaria pigmentosa become manifest after the cessation of PUVA treatment probably because new mast cells differentiate from bone marrow-derived precursors.

Psoralen photochemotherapy

Psoralens and sunlight have been used by the Egyptians and Indians for hundreds of years for the treatment of vitiligo. The combination of oral psoralens and artificial ultraviolet A (PUVA) therapy was approved for the management of severe psoriasis by the Food and Drug Administration in 1982. Since then PUVA therapy has been found to be an effective modality in the treatment of many cutaneous conditions. When properly administered, the major short-term side effects are minimal. The long-term side effects may include an increased risk of squamous cell carcinoma, atypical cutaneous pigmentation, accelerated skin aging, and ophthalmologic abnormalities. By careful patient selection and limiting the cumulative UVA dosage and frequency by using combinations or alternative therapies, these side effects may be reduced. Continued reporting of carefully carried out long-term prospective studies will provide us with more knowledge of the long-term side effects of PUVA. In the meantime, for each patient on PUVA therapy the risk/benefit ratio should be carefully considered.

Treatment of chronic urticaria with PUVA or UVA plus placebo: a double-blind study

Chronic urticaria is a disease for which the available range of treatment modalities is limited. Ultraviolet radiation has recently been shown to affect histamine release from mast cells. We therefore studied the effects of PUVA and UVA on chronic urticaria. Nineteen patients took part in the study, which was designed as a randomized double-blind study. Eleven patients received PUVA, and 8 received UVA plus a placebo. In the PUVA group, 7 patients showed improvement, 3 noticed no change, and 1 became worse. In the group that received UVA plus placebo, 5 patients experienced an improvement, whereas the other 3 showed no change. The differences between the groups were not statistically significant. However, the probability of achieving this degree of improvement in both groups just by chance is less than 1%. Consequently, the improvement noted could have been due to either UVA alone or a placebo effect. It is concluded that PUVA is not better than UVA in the treatment of chronic urticaria.

A review of pruritus

This article reviews the neurophysiology of pruritus and presents evidence that itch is a separate modality from pain, rather than a submodality of pain. The numerous suggested pruritogens are reviewed, and evidence supporting each one is critically examined. The systemic causes of generalized pruritus are reviewed, with detailed review of the literature on uremic pruritus, cholestatic pruritus, and the pruritus associated with polycythemia vera. The specific treatments used for each of these conditions are reviewed, as well as the use of antihistamines in generalized pruritus. An approach to the workup of a patient with pruritus is suggested.

The spectrum of mastocytosis

Mastocytosis represents a spectrum of clinical disorders that results from an aberrant proliferation of tissue mast cells. This disease process may be confined to the skin (cutaneous mastocytosis) or may involve multiple organs (systemic mastocytosis). Parameters that are useful in differentiating cutaneous from systemic disorders include patient age, symptom complex, and clinical signs. A wide range of clinical symptoms may be encountered in patients with mastocytosis which result from the release of pharmacologically potent mast cell mediators. Distinct cutaneous patterns resulting from skin mast cell infiltrates can be helpful in identifying patients with systemic involvement. The diagnosis of mastocytosis is confirmed by demonstrating increased tissue mast cells in involved organs. The overall prognosis for patients with proliferative mast cell disease is relatively good, although a small percentage are at risk for developing a fatal neoplastic disorder (malignant mastocytosis). Treatment of mastocytosis is directed at both inhibiting mast cell degranulation and blocking the potential systemic effects of released secretory products. Future therapeutic advances depend upon an improved understanding of the basic mechanisms involved in mast cell mediator release and the forces that govern mast cell growth and development.

Chromatin dynamics. Fast and slow modes of nucleosome movement revealed through psoralen binding and repair

Psoralen adducts, when formed in DNA at low frequencies that permit extensive survival of normal and repair-deficient cells, are found in both linker and core regions of nucleosomes, but are slightly enriched in the linker sites. The relative frequencies of adducts obtained with 5-methylisopsoralen and angelicin, which form only monoadducts, and 8-methoxypsoralen and trimethylpsoralen, which form monoadducts and cross-links, represent an enrichment in linker DNA that is approx. 2-3-fold higher per nucleotide than in core DNA. 5-Methylisopsoralen monoadducts, which are initially in linker DNA, become randomized during 12 h of growth. This suggests a slow lateral movement of nucleosomes with respect to DNA and implies that linker and core regions of DNA are not permanent assignments. Randomization of 5-methylisopsoralen adducts is independent of the synthesis of DNA, RNA, protein, or poly(ADP-ribose) and is also independent of DNA repair. Excision repair of these adducts, in contrast, causes rapid local changes in nucleosome conformation and an initial increase in staphylococcal nuclease sensitivity that reverts to the sensitivity of bulk chromatin in less than 1 h. Chromatin, therefore, can undergo at least two distinct dynamic changes under physiological conditions: a slow randomization of the nucleosomes with respect to DNA, and a rapid but transient local rearrangement to facilitate repair.

Phototherapy of urticaria pigmentosa: clinical response and changes of cutaneous reactivity, histamine and chemotactic leukotrienes

Ten patients with moderate to very severe urticaria pigmentosa were studied for the therapeutic effect of photochemotherapy (PUVA; six adults) and selective ultraviolet phototherapy (SUP; four adolescents). Despite a high mean PUVA dosage (138.6 +/- 63.4 J/cm2), only two patients had a very good response, while three had a good response and one had a fair response. On the reduction of the frequency of treatments, the symptoms gradually recurred, and several months after the discontinuation of therapy, the clinical status had reached the level prior to PUVA. The results with SUP were even less encouraging. A number of biophysical and biochemical parameters of the skin were studied in five patients before PUVA treatment, immediately after several months of PUVA treatment and again 5 months after the discontinuation of PUVA treatment. Weal and erythema reactions to intracutaneous skin tests remained unchanged after PUVA, while wealing with topically applied dimethylsulfoxide (DMSO) decreased. Transepidermal water loss was markedly reduced over DMSO weals. Histamine levels, which were elevated in lesional but not in normal skin, dropped with PUVA treatment, but after the discontinuation of treatment, they increased again in the lesions. On reverse-phase high-performance liquid chromatography, two main chemotactic factors, leukotriene B4 and 5-HETE, were identified in lesional skin. Chemotactic activity was elevated in both lesional and uninvolved patient skin, reached normal levels at both sites after PUVA and maintained these low levels for several months after the discontinuation of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Urticaria pigmentosa responsive to nifedipine

A patient with symptomatic urticaria pigmentosa who responded to nifedipine therapy is reported. Relief from cold-induced urtication and flushing was obtained with 10 mg taken orally three times daily. Calcium influx is an early step in the degranulation of mast cells. We hypothesize that the beneficial effect of nifedipine was due to calcium-channel blockade causing elevation of the mast cell threshold for degranulation.

Response of cutaneous mast cells to PUVA in patients with urticaria pigmentosa: histomorphometric, ultrastructural, and biochemical investigations

In six patients with urticaria pigmentosa, population density and ultrastructure of the cutaneous mast cells and histamine levels of the lesional skin were studied before, immediately after, and again 5-8 months after photochemotherapy (PUVA). Immediately after PUVA, the total mast cell number was not reduced, but on separate analysis of the intradermal distribution, significantly fewer mast cells were found in the papillary dermis and correspondingly more mast cells in the adjacent upper dermis. On electron microscopic examination, 4% of the mast cell granules were immature before and 27% after PUVA therapy, based on the lower electron density of the granular matrix. This was associated with a markedly lower histamine content of the lesional skin. Five to eight months after recovery from PUVA, the morphologic changes and the histamine levels had all returned to the pre-PUVA status. These findings were paralleled by a reversal of all clinical beneficial effects that had been observed with PUVA.