Assessment of psychological aspects during systemic provocation tests in patients with pseudoallergic drug reactions

BACKGROUND

Basic mechanisms of pseudoallergic drug reactions as well as a possible role of the psyche are currently unknown.

OBJECTIVE

Examination of psychological status and reactions during diagnostic provocation tests in patients with previous pseudoallergic reactions to drugs.

SUBJECTS AND METHODS

Ten inpatients, admitted for provocation tests, were studied in a double-blind, placebo-controlled setting, with inventories of anxiety and depression being measured at baseline and psychological reactions and symptoms being recorded daily by patients and the attending physician.

RESULTS

Patients reported more than twice as many symptoms as the physician, independent of the type of exposure. While the basic psychological profile of the patients was normal, anxiety trait and state values were high during testing, with a significant increase depending on whether the patients thought they had received a drug or a placebo. Similarly, frequency of symptoms was dependent on the patients' perception of the type of exposure.

CONCLUSION

These findings demonstrate a high level of anxiety during systemic provocation tests in patients with previous pseudoallergic drug reactions, raising serious questions as to the diagnostic validity of the routine application of this testing.

EAACI/GA2LEN/EDF guideline: management of urticaria

This guideline is the result of a consensus reached during a panel discussion at the second International Consensus Meeting on Urticara, Urticaria 2004, a joint initiative of the EAACI Dermatology Section and GA2LEN. Urticaria has a profound impact on the quality of life, and effective treatment is therefore required. The recommended first line treatment are nonsedating H1 antihistamines. They have proven to be effective in double-blind controlled studies, but dosages increased up to fourfold over the recommended doses may be necessary. However, for different urticaria subtypes and in view of individual variation in the course of the disease and response to treatment, additional or alternative therapies may be required. Immunosuppressive drugs like cyclosporin A and corticosteroids are not recommended for long-term treatment due to unavoidable severe adverse effects. This guideline was, in addition, accepted by the European Dermatology Forum (EDF) and formally approved by the European Union of Medical Specialists (UEMS).

EAACI/GA2LEN/EDF guideline: definition, classification and diagnosis of urticaria

This guideline is the result of a consensus reached during a panel discussion at the 2nd International Consensus Meeting on Urticaria, Urticaria 2004, a joint initiative of the European Academy of Allergology and Clinical Immunology Dermatology Section and the European Union (EU)-funded network of excellence, GA2LEN. It covers the definition and classification of urticaria, taking into account the recent progress in identifying causes, eliciting factors and pathomechanisms of this disease. We have outlined useful diagnostic approaches for different subtypes of urticaria. This guideline was, in addition, accepted by the European Dermatology Forum (EDF) and was formally approved by the European Union of Medical Specialists (UEMS).

Differential expression of angiotensin receptors in human cutaneous wound healing

BACKGROUND

Angiotensin AT1 and AT2 receptors are expressed in human skin. Furthermore, AT2 receptors have been reported to be upregulated during tissue repair and remodelling in various noncutaneous human tissues.

OBJECTIVES

Detection of alterations in angiotensin II receptor expression during wound healing in human skin.

METHODS

Three models were employed. (i) Primary human keratinocytes were razor scraped in culture flasks and alterations in the expression of angiotensin receptor mRNA determined by semiquantitative reverse transcription-polymerase chain reaction for 1-12 h thereafter. (ii) Early wound healing (48 h after cutting) was studied in punch biopsies from human skin ex vivo by means of immunohistochemical staining using polyclonal antibodies against the AT1 or AT2 receptor. (iii) In vivo wound healing was studied in sections of human cutaneous scars by immunohistochemistry to determine receptor expression early (2 days) and late (2 weeks-3 months) after surgery.

RESULTS

In all experimental settings, an upregulation of both receptor subtypes was noticed after wounding. Immunohistochemically stained skin sections showed a stronger expression of AT2 than of AT1 receptors within the area of scarring. Enhanced receptor expression was detectable as early as 24 h after injury and lasted for up to 3 months.

CONCLUSIONS

From these data, we conclude that angiotensin AT1 and AT2 receptors are upregulated in human cutaneous wounds, giving further support to the concept that angiotensin II plays a role even at an early stage during cutaneous wound healing.

Gene expression and regulation of transcription factor activator protein-2 alpha in human mast cells

BACKGROUND

The transcription factor activator protein (AP)-2 regulates cell-type specific gene expression during development and differentiation, but its role in mast cell development has so far not been explored.

METHODS

Gene expression and regulation of AP2 was assessed in normal skin, diseases with increased mast cell numbers, and in vitro models of mast cell differentiation.

RESULTS

AP-2alpha-protein was not detectable in normal skin but in mastocytoma lesional mast cells. AP-2alpha-mRNA and -protein were also detected in leukemic mast cells (HMC-1), in the adherent fraction of peripheral blood (PBMC) and umbilical cord blood mononuclear cells (CBMC), and AP-2alpha-mRNA at low levels in isolated-purified mast cells. During culture with fibroblast supernatants or SCF, AP-2alpha-mRNA was de novo expressed in KU812-cells, maintained at about the same level in PBMC and CBMC, and upregulated in HMC-1-cells. On extended culture, a down-regulation was noted at mRNA and/or protein levels. In contrast, tryptase expression increased in all cells throughout culture, as did c-Kit in normal cells, whereas in both leukemic cell lines, c-Kit was maintained unchanged at about the same level.

CONCLUSIONS

These findings suggest a continuous activation of AP-2alpha in mastocytomas and mast cell leukemia and its transient upregulation during c-Kit dependent early steps of normal mast cell differentiation.

Retinoic acid inhibits CD40 plus IL-4 mediated IgE production through alterations of sCD23, sCD54 and IL-6 production

BACKGROUND

All-trans retinoic acid (ATRA) inhibits IgE synthesis from anti-CD40 plus IL-4 stimulated human B lymphocytes.

OBJECTIVE

To study the underlying mechanisms, we examined here molecules which are known to have an impact on IgE production, namely CD23, CD54 and IL-6.

METHODS

Human anti-CD40 plus IL-4 stimulated B cells were cultured in the absence and presence of ATRA (10(-6)-10(-10) M). ELISAs were performed to determine soluble (s) CD23 and sCD54, IL-6 and IgE-levels. CD23 and CD54 surface expression were determined by flow cytometric analysis. Semiquantitative-RT-PCR was employed to analyse IL-6, CD23 and CD54 mRNA expression.

RESULTS

ATRA induced a dose-dependent increase of percent CD23 (3.4 fold) or CD54 (1.6 fold) positive B cells. At the mRNA level, this was reflected by a modest increase of CD54 mRNA (46.5 +/- 15.8%) only. By contrast, levels of sCD54 were decreased dose-dependently in the presence of ATRA (56.6 +/- 7.6%). Cytokine analysis showed that IL-6 secretion was significantly inhibited by ATRA (53.6 +/- 0.6%) and also IL-6 mRNA synthesis was reduced (66.3 +/- 11.6%). The observed inhibition of IgE production mediated by ATRA was significantly reversed to 90.5 +/- 12% by the addition of 100 pg/mL recombinant IL-6.

CONCLUSIONS

ATRA interferes through several pathways with the anti-CD40 plus IL-4 mediated B cell activation, namely IL-6, CD23 and CD54.

Prior immunisation of patients with malignant melanoma with vaccinia or BCG is associated with better survival. An European Organization for Research and Treatment of Cancer cohort study on 542 patients

There is increasing evidence that infections and vaccinations play an important role in the normal maturation of the immune system. It was therefore of interest to determine whether these immune events also affect the prognosis of melanoma patients. A cohort study of 542 melanoma patients in six European countries and Israel was conducted. Patients were followed up for a mean of 5 years and overall survival was recorded. Biometric evaluations included Kaplan-Meier estimates of survival over time and Hazard Ratios (HRs), taking into account all known prognostic factors. During the follow-up between 1993 and 2002, 182 of the 542 patients (34%) died. Survival curves, related to Breslow's thickness as the most important prognostic marker, were in accordance with those observed in previous studies where the cause of death was known to be due to disseminated melanoma. In a separate analysis of patients, vaccinated with vaccinia or Bacille Calmette-Guerin (BCG), HRs and the corresponding 95% Confidence Intervals (CIs) were 0.52 (0.34-0.79) and 0.69 (0.49-0.98), respectively. Joint analyses yielded HRs (and 95% CIs) of 0.55 (0.34-0.89) for patients vaccinated with vaccinia, 0.75 (0.30-1.86) with BCG, and 0.41 (0.25-0.69) with both vaccines. In contrast, infectious diseases occurring before the excision of the tumour had little, or, at the most, a minor influence on the outcome of the melanoma patients. These data reveal, for the first time, that vaccination with vaccinia in early life significantly prolongs the survival of patients with a malignant tumour after initial surgical management. BCG vaccination seems to have a similar, although weaker, effect. The underlying immune mechanisms involved remain to be determined.

Mast cells and vasculature in atopic dermatitis--potential stimulus of neoangiogenesis

BACKGROUND

Atopic dermatitis skin lesions are characterized by inflammatory changes and epithelial hyperplasia requiring angiogenesis. As mast cells may participate in this process via bidirectional secretion of tissue-damaging enzymes and pro-angiogenic factors, the present study aimed to assess the occurrence and possible function of mast cells in the papillary dermis and in epidermal layers of atopic dermatitis lesions.

METHODS

Semi-thin and serial sections in combination with immunohistochemistry, histochemistry and proliferating cell nuclear antigen (PCNA)-activity assays were used and related to epidermal thickness and targeted gene expression studies.

RESULTS

Mast cells were located in the papillary dermis and migrated through the basal lamina into the epidermis of atopic dermatitis lesions. An increased PCNA-activity in cells of superficial epidermal layers indicated an activation of keratinocytes and stimulation of endothelial growth. Only approximately 30% of the papillary mast cells stained with the tryptase were toluidin-blue-positive, and approximately 80% were chymase positive. A high number of mast cells expressed c-kit. Most papillary and epidermal mast cells were localized close to endothelial cells. Vascular expression of endoglin (CD105) demonstrated neoangiogenic processes. Mast cells stimulation led to the expression of proangiogenic factors. Also, gene expression of tissue-damaging factors such as matrix metalloproteinases was increased.

CONCLUSIONS

These data suggest that in atopic dermatitis, mast cells are abundantly localized close to and within the epidermis where they may stimulate neoangiogenesis. Via the new vessels, inflammatory cells, together with complement components and antibodies, can be transported to the epidermis to aid in the defense against environmental antigens and to maintain chronic inflammation.

The transcription factor profile of human mast cells in comparison with monocytes and granulocytes

Expression profiles of mRNAs and proteins for various transcription factors were determined for human skin mast cells (sMCs), leukemic HMC-1 MCs, monocytes and granulocytes. By quantitative RT-PCR, sMCs expressed lower levels of c-fos, PU.1, C/EBPalpha, and C/EBPepsilon than monocytes and granulocytes, but higher levels of MITF, SCL, GATA-1 and GATA-2. At the protein level, MITF, SCL, GATA-2, Elf-1 and c-fos were clearly detectable in sMCs. With the exception of c-fos, these proteins were absent or expressed only slightly in monocytes and granulocytes. The expression of NF-E2p45, GATA-1, PU.1, Ets-1, C/EBPalpha and C/EBPepsilon was below the detection limit in sMCs, but detectable in other myelocytes. The high expression of SCL and GATA-2 in sMCs is reminiscent of stem cells. The absence of C/EBPvarepsilon in sMCs, but strong expression in HMC-1, suggests it may impair MC maturation. In summary, mature human MCs can be characterized as C/EBPalpha(low), C/EBPvarepsilon-, PU.1(low), GATA-1(low), GATA-2+, SCL+, MITF(high).

Crossreacting IgG antibodies against fox mite antigens in human scabies

Scabies continues to be an important parasitic disease of mammals. There remain, however, major gaps in the understanding of the human host immune response, and a simple diagnostic test is lacking. In contrast to human mites, red fox mites (Sarcoptes scabiei var. vulpis) can be collected easily and have been used, due to crossreactivity, for enzyme-linked immunosorbent assay (ELISA) studies in dogs and pigs. We wanted to investigate the possibility that crossreactivity might also exist for the human mite, and determined titers against fox mite antigens by ELISA in 41 patients with scabies. Specific IgG was significantly higher in patients with scabies than in healthy controls (P=0.01). The sensitivity was, however, only 48%, although it increased slightly during treatment (P=0.86). A positive correlation was also noted between disease duration and severity of infestation (r=0.5), with specific IgG titers increasing in parallel with severity of symptoms (P=0.01). Patients with symptomatic scabies for more than 4 weeks had furthermore significantly higher IgG titers than patients with a shorter duration of disease (P=0.007). In conclusion, these findings demonstrate IgG antibodies in human scabies that crossreact with fox mite antigens, thus encouraging the search for improved ELISAs with more specific mite antigens to produce a more sensitive detection system for scabies in humans.

Muckle-Wells syndrome: clinical and histological skin findings compatible with cold air urticaria in a large kindred

BACKGROUND

Muckle-Wells syndrome is a rare familial disease with autosomal dominant inheritance, characterized by cold sensitivity and polyarthralgias since childhood, with possible later development of nerve deafness and renal amyloidosis. The nature of the skin manifestations is, however, not well characterized.

OBJECTIVES

To clarify the nature of cutaneous cold sensitivity in patients with Muckle-Wells syndrome by studying clinical aspects and histological features.

METHODS

Eighteen members of a family with Muckle-Wells syndrome and the recently identified mutation of the CIAS1 gene at locus 260 of chromosome 1q44 were available for study. Examination included a thorough history, physical examination and a battery of laboratory tests. In two brothers, standard cold contact and cold air provocation tests were performed, as were biopsies from normal and lesional skin.

RESULTS

All affected family members reported an increased sensitivity to cold, dampness or changes in temperature, and most had arthritis and conjunctivitis. Eight had developed hearing loss, four renal involvement, and amyloid deposits were found in three of five patients in whom rectal biopsies were performed. Laboratory tests showed leucocytosis and elevated C-reactive protein, but no serum cold agglutinins and cryoglobulins. Skin eruptions, with weals of 0.2-3 cm, lasted from 5 to 24 h and were associated with local itching or pain as well as fever, malaise and chills. On cold provocation of two patients, lesions could be reproduced by cold air, but not by contact with an ice cube or cold water. On histology, there was increased vasodilatation, marked infiltration with neutrophils and monocytes/macrophages, and increased expression of beta 2 integrins in lesional vs. normal skin. Numbers of mast cells as well as expression of interleukin-3 and tumour necrosis factor-alpha were unchanged.

CONCLUSIONS

Cold-induced skin lesions in Muckle-Wells syndrome represent typical generalized cold air/wind inflammatory reactions, as also observed in familial cold urticaria. Microscopic features are similar to those observed in other types of urticaria.

Dithranol in an Emulsifying Oil Base (Bio-Wash-Oil) for the Treatment of Psoriasis of the Scalp

On the scalp, dithranol has been studied in only a few trials. The dithranol molecule that contains both hydrophilic and lipophilic centers can be incorporated into detergents and allows easy removal from hair. This property has led to the incorporation of dithranol in an emulsifying oil base (bio-wash-oil). The formulation has been used routinely for more than two decades in East Germany. We reexamined the efficacy and safety of dithranol in bio-wash-oil and compared it to dithranol embedded in crystalline monoglycerides (Micanol) in patients with psoriasis of the scalp. In a prospective, parallel group study, 64 patients attending a day-care clinic were randomly allocated to 3 treatment groups: (1) dithranol in bio-wash-oil; (2) Micanol cream, and (3) Micanol cream in bio-wash-oil. Treatment was carried out for 3 weeks and results assessed using a modified Psoriasis Area and Severity Index score. Dithranol in bio-wash-oil resulted in a reduction in the score of 34% on day 7 and 57% on day 14. This was significantly better than in groups 2 and 3, as were the overall response and patients' assessment at the end of treatment (p < 0.05). Dithranol in a bio-wash-oil is an effective, well-tolerated and low-priced treatment in psoriasis of the scalp.

Miliaria crystallina in an intensive care setting

Drop-like, transient blisters of miliaria crystallina may develop with focal intensity of heat within the skin, such as occurs in tropical climates or during febrile episodes. Miliaria crystallina develops due to a transient poral closure of the sweat duct opening, resulting in obstruction of free flow of eccrine sweat and retention in a vesicle below the skin surface. Dual cholinergic and adrenergic sweat gland innervation is influenced by a variety of medications used in intensive care patients. We present two febrile intensive care patients in whom enhanced alpha-adrenergic stimulation of sweat gland myoepithelia may have led to miliaria crystallina.

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.

Impact of vaccinations and infectious diseases on the risk of melanoma--evaluation of an EORTC case-control study

A significant correlation between a reduced risk of melanoma and BCG and vaccinia vaccination in early childhood or infectious diseases later in life has already been reported from the FEBrile Infections and Melanoma (FEBIM) multicentre case-control study. This correlation is further evaluated in this study based on 603 incident cases of malignant melanoma and 627 population controls in six European countries and Israel by means of a joint analysis of the influence of vaccinations and infectious diseases. In addition, the previously unconsidered impact of influenza vaccinations is evaluated for the whole study population. The strong effects of the frequently given BCG and vaccinia vaccinations in early childhood, as well as of uncommon previous severe infectious diseases, were apparently not cumulative. With the Odds Ratio (OR) being set at 1 in the absence of vaccinations and infectious diseases, the OR dropped to 0.37 (95% Confidence Interval (CI): 0.10-1.42) when subjects had experienced one or more severe infectious diseases, associated with a fever of > 38.5 degrees C, and had not been vaccinated with BCG or vaccinia. The OR was 0.29 (CI: 0.15-0.57) in those who had had a severe infectious disease and were vaccinated with either BCG or vaccinia and 0.33 (CI: 0.17-0.65) for those with 1 or more severe infectious diseases and who had received both vaccinations. We conclude that both vaccinations as well as previous episodes of having a severe infectious disease induced the same protective mechanism with regards to the risk of melanoma. Because of a 'masking effect' by the vaccinia vaccination, the protective effect of the BCG vaccination and of certain infectious diseases against cancer has remained undetected. The vaccinations contributed more to the protection of the population than a previous episode of having an infectious disease. In view of the termination of vaccinations with vaccinia in all countries and of BCG in many of them, these findings call for a re-evaluation of vaccination strategies.

Decreased cutaneous expression of stem cell factor and of the p75NGF receptor in urticaria

BACKGROUND

Mast cells, the main effector cells in urticaria, have been reported to be increased in number in lesional and nonlesional skin of urticaria patients, but the underlying mechanisms have so far not been studied. Serum NGF has however, been reported to be increased in urticaria.

OBJECTIVES

We have therefore explored the potential involvement of known mast cell growth modulating factors in urticaria.

METHODS

Tissue sections from patients with different types of urticaria and healthy controls were studied for the immunohistochemical expression of known mast cell growth factors (stem cell factor, SCF; nerve growth factor, NGF), of the inhibitory granulocyte-macrophage colony-stimulating factor (GM-CSF), and of the corresponding receptors, using the alkaline phosphatase-antialkaline phosphatase technique.

RESULTS

Compared to skin of normal controls, staining for SCF, but not for NGF and GM-CSF, was significantly decreased in epidermis, endothelium and perivascular cells in lesional and nonlesional skin of all urticarias. On separate analysis of urticaria subtypes, decreased expression reached significance only in delayed pressure urticaria. Expression of the p75NGF receptor (p75NGFR) was also significantly decreased on endothelium and on perivascular cells of lesional and nonlesional skin in all urticarias. On evaluation of serial sections, p75NGFR expression was also decreased on c-Kit positive dermal mast cells. In contrast, expression of the NGF receptor tyrosine kinase and of the SCF and GM-CSF receptors was unchanged.

CONCLUSIONS

These findings show that SCF and p75NGFR are selectively and systemically down-regulated in the skin of urticaria patients and may represent a negative feedback to increased mast cell reactivity and proliferation.

Nine-year follow-up of a case of Grzybowski type multiple keratoacanthomas and failure to demonstrate human papillomavirus

We describe a patient with a 9-year history of generalized eruptive keratoacanthoma (KA) of the Grzybowski type whose multiple skin lesions showed steady progression, resulting in a sclerotic, mask-like facial expression and ectropion. Eleven tumour biopsies representing lesions of different stages and localizations (erupting and regressing KAs, biopsies from non-involved light-protected and light-exposed skin, dermatosclerosis and squamous cell carcinomas) were analysed for human papillomavirus (HPV) sequences using a polymerase chain reaction approach capable of detecting the majority of all presently known HPV genotypes. None of the biopsy specimens proved to be HPV-positive, although HPV was detected in weakly and heavily affected control specimens by the method applied. These findings suggest an HPV-independent aetiology of this rare type of multiple KA.

Laser-induced weal and flare reactions: clinical aspects and pharmacological modulation

BACKGROUND

Among the adverse effects of cutaneous laser therapy, weal and flare reactions immediately after treatment have received little attention, and the pathomechanisms are unclear.

OBJECTIVES

To study clinical features and possible mechanisms of laser-induced weal and flare reactions in order to identify means of possible therapeutic intervention.

METHODS

Normal skin from the inner arm of 20 volunteers was treated with an argon laser, and the size of weal and flare reactions was measured over a 60-min period. Skin biopsies were taken from four volunteers before and up to 24 h after laser treatment and examined histologically and immunohistologically. Possible underlying mechanisms were also explored using various topical or systemic pharmacological agents.

RESULTS

Wealing was noted in 19 of 20, and flare reactions in all volunteers, with peak values at 15 min. Skin biopsies showed central coagulation of the tissue, cleft formation between epidermis and dermis, normal numbers of morphologically intact mast cells on toluidine blue staining close to the lesion, and only minor upregulation of endothelial and leucocyte adhesion molecules. In agreement with these findings, pretreatment with acetylsalicylic acid, the H1-blocker loratadine and triamcinolone cream was ineffective or resulted in a non-significant reduction of weal and flare reactions. In contrast, local anaesthetics as well as neuropeptide depletion of skin with capsaicin abolished the reactions almost completely.

CONCLUSIONS

Transient weal and flare reactions in response to laser treatment occur in almost all persons and are based primarily on a neurogenic rather than a histamine- or mast cell-dependent mechanism.

Management of urticaria: a consensus report

This consensus report is the result of a panel discussion during the International Clinically Oriented ESDR Symposium Urticaria 2000. Urticaria has a profound impact on the quality of life and effective treatment is required. The most important are nonsedating H1 antihistamines. They have been proven to be effective in double-blind controlled studies, but concentrations higher than those recommended may be necessary. Due to different urticaria subtypes and the individual variation in the course of the disease and response to treatment, however, alternative therapies may be required. Immunosuppressive drugs like cyclosporine A and corticosteroids should not be used long term due to undesirable side-effects.

Mastocytosis: review of clinical and experimental aspects

Mastcytosis is a rare disease characterized by an abnormal increase of mast cells in tissues. The skin is the organ most frequently involved, but mast cells also accumulate in the bone marrow, gastrointestinal tract, lymph nodes, spleen, and liver. Recent studies suggest that activating mutations of c-kit, a protooncogene encoding for the receptor (kit) of stem cell factor, are a possible cause of some forms of mastocytosis. In addition, an increased rate of chromosomal aberrations has been found. Despite significant advances in research on mastocytosis, curative treatment is not yet available. Current management is based on avoidance of mediator-releasing triggers and symptomatic treatment.