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Summary Background Chronic urticaria (CU) is an autoimmune process in some patients. An association between CU and autoimmune thyroid disease has also previously been proposed. Our group has identified functionally significant histamine-releasing autoantibodies in one subset of CU patients (subset 1), predicted by positive autologous intradermal serum tests and positive histamine release from donor basophil leucocytes in vitro. Sera from a second subset of patients (subset 2), all of whom had positive autologous intradermal serum tests, failed to release histamine from donor basophils. A final disease subset (subset 3) has no identifiable skin reactivity (negative autologous serum skin test) or in vitro histamine releasing activity. Objectives In order to examine further the possible relationships between thyroid autoimmunity, thyroid dysfunction and CU, we have examined thyroid autoantibodies and thyroid-stimulating hormone (TSH) levels (an indirect measure of thyroid dysfunction) in the three CU subsets. Patients/methods We studied 182 patients (69% female), of whom 90 had a positive autologous intradermal serum test. Results Eighteen skin test-positive and four skin test-negative patients had thyroid microsomal antibodies (TMA). TSH outside the normal range was found in 13 skin test-positive and one skin test-negative patient. These findings represent clustering of TMA positivity [risk ratio (RR) 4·06, 95% confidence interval (CI) 1·56–10·6] and of abnormal thyroid function (RR 15·5, CI 2·07–11·6) among the skin test-positive patients. However, in the overall study group an elevated TSH was present in seven patients (3·8%, CI 1·6–7·8) comparable to the 5% expected prevalence in the community. Thyroglobulin antibodies (TGA) were present in two of 182 patients. Conclusions There were significant differences between skin test-positive and skin test-negative patients with regard to autoimmune thyroid disease. Evidence for autoimmune thyroid disease and abnormal thyroid function was largely found among the skin test-positive patients, supporting the theory of an autoimmune aetiology in this group.

Delayed pressure urticaria is a mechanical urticaria in which pressure causes whealing. Delayed cutaneous erythema and edema occur in association with marked subcutaneous swelling after the application of a sustained pressure stimulus to the skin. The earliest reports and theories of the pathogenesis of delayed pressure urticaria are summarized. Detailed attention is given to making the diagnosis by taking a history and provoking the lesions. The clinical features and natural history are considered. The effects of the disorder on quality of life are delineated, and management strategies are suggested.

Urticaria is predominantly due to release of mast cell mediators, mainly histamine. Chronic idiopathic urticaria, in which disease activity continues on most days for more than 6 weeks and there is no evidence of a physical urticaria or urticarial vasculitis, is common. An external cause is rarely identified even if a thorough history and appropriate investigation based on this are undertaken. However, approximately 50% of patients with chronic idiopathic urticaria (CIU) have a serum histamine releasing factor present. In one-third of patients with CIU this is an IgG autoantibody directed against the high affinity IgE receptor (FceRI) or less frequently against IgE. Patients with autoinimune urticaria, are clinically more severe. Urticaria can affect the quality of life markedly, being comparable to that of patients awaiting triple coronary by-pass surgery. The rational management of urticaria takes account of likely causes and mediators involved. However explanation and attention to general measures such as minimizing stress, overheating and alcohol are important. Aspirin, nonsteroidal anti-inflammatory drugs and opiates should be avoided if possible. Exclusion diets such as of food colourings and additives may be of some value to a limited number of patients. Second- and third-generation low sedation H1 antagonists are the treatment of choice and improve many patients. Addition of an H2 antagonist or a mast cell stabilizing drug may provide additional benefit for a few. There are reports that leukotriene receptor antagonists improve some patients. Oral steroids are reserved if possible for severe exacerbation of chronic urticaria, and disabling pressure urticaria. Third-line therapies involving immunosuppressive agents are only appropriate for patients with chronic urticaria refractory to other measures, and usually autoimmune. The encouraging results using short courses of oral cyclosporin, high dose intravenous immunoglobulin and plasmapheresis need to be confirmed in placebo-controlled trials, in patients with or without demonstrable serum histamine releasing activity.

SummaryBackground Self-administered adrenaline syringes may be prescribed for patients at risk of life-threatening episodes of angio-oedema or anaphylaxis. Objectives To determine whether patients are able to use these syringes appropriately and adequately. Methods Twenty-nine consecutive patients who had been prescribed self-administered adrenaline syringes for severe angio-oedema were recruited. All completed a questionnaire (unsupervised), and were asked to demonstrate how to use a dummy syringe. Results Three of 29 (10%) patients had been prescribed syringes in the absence of severe angio-oedema or collapse. Seventeen of 29 (59%) patients had been prescribed two syringes, and 21 of 29 (72%) kept a syringe with them at all times. Twenty of 28 (71%) patients had had the use of a syringe demonstrated to them with the initial prescription, but two of 29 (7%) had never been shown how to use it. Only six of 26 (23%) patients had been told to telephone for an ambulance after using a syringe. Only seven of 29 (24%) patients would use a syringe for an episode of collapse, whereas eight of 28 (29%) would use one for an episode of lip swelling. Nine of 21 (43%) patients had not been warned about adverse effects, although 13 of 20 (65%) given adrenaline had had at least one adverse effect. Of the 25 patients asked to demonstrate their use of a syringe, only 14 (56%) were able to perform all steps correctly, and three (12%) were unable to perform any of the steps. Despite this, all 29 patients felt confident about giving themselves an injection, and most felt more secure having been prescribed syringes. Conclusions As self-administered adrenaline syringes are prescribed for life-threatening events, it is vital that they are given to appropriate patients with adequate written instructions and proper demonstration at the time of the initial prescription. As a result of this study we have developed a more detailed patient information leaflet, and all patients are shown how to use a syringe for a second time when attending the clinic for follow-up.

Chronic idiopathic urticaria (CIU) may be severe and refractory to standard therapies. We describe two patients with CIU, neither of whom had detectable autoantibodies, in whom control of the disease was achieved with methotrexate.

Background Vulval carcinoma is a relatively rare disorder that may have various aetiologies. Objectives To document the features and outcome in a series of patients with this disorder. Methods Retrospective analysis of patients presenting to a vulval clinic over a 5-year period. Results Twenty-one women presented with a squamous cell carcinoma (SCC) and two with a verrucous carcinoma (VC). The age range was 43–83 years. Twenty-one had well-established (1–30 years) vulval symptoms prior to developing their tumour. Specific tumour-related symptoms ranged from 3 weeks to 11 months. Eight had had a prior diagnosis of lichen sclerosus (LS) or lichen planus (LP), only two of whom were on regular treatment and follow-up. At presentation, 12 patients had clinical signs of LS, three of LP, and five had some changes of both LS and LP. Two patients had multifocal vulval intraepithelial neoplasia (VIN3). Only one had no evidence of any background vulval skin disease. The commonest histological changes noted in the epithelium either adjacent to or distant from the SCC were those of atrophic LS (n = 8), LS with squamous cell hyperplasia (n = 3), LS with hyperplastic foci and lichenoid infiltrate (n = 4), and LS with differentiated VIN3 (n = 1). Four cases demonstrated the changes of LP, and three showed VIN3. All patients were treated surgically and, in those who had lymphadenectomy, four had positive nodes. There have been two deaths due to metastatic disease, and one further patient has developed a second primary SCC at a different site. Conclusions An underlying skin disorder prior to the development of their carcinoma was found in 22 of 23 patients with vulval SCC and is therefore an important risk factor.

We report two cases of Schnitzler's syndrome in which anti-interleukin-1α autoantibodies and functional autoantibodies against the high affinity IgE receptor (FceRIα) or against IgE were absent. One patient responded well to TL-01 phototherapy, a treatment which may be considered in patients with Schnitzler's syndrome if, as is usually the case, they are unresponsive to antihistamine therapy.

The major histocompatibility complex (MHC) acts as a marker for self during T-cell ontogeny and is associated with the pathogenesis of many autoimmune diseases. Recent investigations have shown about 30% of patients with chronic idiopathic urticaria (CIU) have IgG autoantibodies against the high-affinity IgE receptor, FcepsilonRI, or IgE. A link between MHC class II alleles and CIU has not been reported previously. DNA was extracted from blood of 100 Caucasian patients with CIU, and the MHC class II type determined using the polymerase chain reaction with sequence-specific primers, testing for DRB and DQB1 alleles. The frequency of alleles in CIU patients was compared with that found in 603 controls. Further human leucocyte antigen (HLA) typing on patient subsets, classified by the patients' responses to intradermal injection of autologous serum and their serum-induced histamine release from basophil leucocytes of healthy donors, was undertaken. HLA DRB1*04 (DR4) and its associated allele, DQB1*0302 (DQ8), are raised in CIU patients compared with a control population (P = 2 x 10-5 and P = 2 x 10-4, respectively). HLA DRB1*15 (DR15) and its associated allele, DQB1*06 (DQ6), are significantly less frequently associated with CIU. The HLA DRB1*04 association is particularly strong (corrected P = 3.6 x 10-6) for patients whose serum has in vivo and in vitro histamine-releasing activity. HLA class II typing is consistent with the concept that CIU is a heterogeneous disease, and supports an autoimmune pathogenesis in a subset of patients.

Background: Previous studies defining the clinical features of patients with chronic idiopathic urticaria (CIU) were performed before the identification of functional autoantibodies against FcϵRI and/or IgE, now known to be present in approximately 30% of patients with CIU. Objective: Our purpose was to determine whether there are differences between patients with and those without autoantibodies in the clinical features or severity of CIU. Methods: The clinical features of 107 patients with CIU were evaluated prospectively. Patients were identified as having functional autoantibodies on the basis of the serum-evoked histamine release in vitro from the basophils of 2 healthy donors. Results: Patients with autoantibodies (31%) had more wheals ( P = .005), a wider distribution of wheals ( P = .009), higher itch scores for the most severe episodes of itching ( P = .002), more systemic symptoms ( P = .03), and lower serum IgE levels ( P Conclusion: The presence of autoantibodies indicates a subset of patients with more severe CIU. (J Am Acad Dermatol 1999;40:443-50.)

Rowell's syndrome is the name given to a distinct group of patients with lupus erythematosus who develop erythema multiforme-like lesions and have a characteristic serological picture. We report a case of a 29-year-old woman of Afro-Caribbean origin who presented with an erythema multiforme-like eruption on the hands. Subsequently she developed painful erythematous swellings on the feet and scaly plaques on the forearm and thigh consistent with subacute cutaneous lupus. She developed a positive antinuclear factor and had positive anti-Ro and anti-La antibodies and a positive rheumatoid factor. All of these features are consistent with Rowell's syndrome which we believe is a rare but distinct variant of cutaneous lupus erythematosus.

Circulating functional autoantibodies to the high-affinity IgE receptor (Fc(epsilon)RI) or to IgE have been found in approximately one third of patients with chronic idiopathic urticaria (CIU).We sought to compare basophil histamine release and basophil numbers in patients with CIU with and without autoantibodies.Basophil histamine release to the anti-Fc(epsilon)RI mAb 22E7, anti-IgE, and formyl-methionyl-leucyl-phenylalanine (fMLP); basophil numbers; and total cellular histamine were measured in 26 patients with CIU and 18 healthy control subjects. Twelve patients were classified as having functional anti-Fc(epsilon)RI and/or anti-IgE autoantibodies on the basis of their serum-evoked histamine release from the basophils of 2 healthy donors.22E7 and anti-IgE, but not fMLP, released less histamine from basophils of patients with CIU than from those of control subjects. Mean+/-SEM maximum histamine release to 22E7 from basophils of control subjects and patients with CIU with and without autoantibodies was 38.5%+/-5.0%, 17.9%+/-6.0% (P =.01), and 1.0%+/-0.3% (P.0001), respectively. Similar results were obtained with anti-IgE, which is dependent on and cross-links cell bound IgE, and 22E7, which directly cross-links the IgE receptor. The mean+/-SEM basophil counts for control subjects and patients with CIU without and with autoantibodies were 52+/-7, 34+/-9 (P =.04), and 5+/-1 (P.0001) x 10(6) cells/L, respectively, and similar changes were found in measurements of total cellular histamine.Patients with autoantibodies have both markedly reduced basophil numbers and basophil histamine release to factors acting through Fc(epsilon)RI, which indicates either a residual pool of functionally distinct basophils or may be a consequence of desensitization of the Fc(epsilon)RI pathway.

Angiotensin-converting enzyme inhibitors (ACEIs) are used increasingly for the treatment of hypertension and chronic heart failure, and they reduce mortality when given after myocardial infarction. Of the patients prescribed these drugs 0.1-0.7% develop angio-oedema, but the association is not widely recognized. In 60% of cases the onset occurs during the first week of treatment; however, it may be considerably delayed. Angio-oedema nearly always occurs on the head and neck, frequently involving the mouth, tongue, pharynx and larynx. The course is unpredictable, and attacks vary in severity from mild to fatal from laryngeal obstruction. Severe ACEI-induced angio-oedema may require emergency treatment with adrenalin and early intubation. The drug should be withdrawn in any patient who presents with ACEI-induced angio-oedema, and treatment continued with an appropriate drug of a different class. Therapy with ACEIs is contraindicated in patients with a prior history of idiopathic angio-oedema, or in patients with hereditary or acquired C1 esterase inhibitor deficiency.

Summary An otherwise healthy 19-year-old pregnant woman developed crusted scabies. She and her husband had previously been treated for scabies. In spite of appropriate treatment both suffered several relapses, and later their infant was also affected. Ultimately, the infection was eradicated. As far as we are aware, this is the first recorded case of crusted scabies occurring in a healthy pregnant woman.

Summary We have investigated the kinetics of the leucocyte infiltrate in delayed pressure urticaria (DPU) in relation to the in vivo expression of the cytokine-regulated cell surface adhesion molecules. E-selectin (endothelial adhesion molecule-1. ELAM-1). intercellular adhesion molecule-1 (ICAM-1), and vascular adhesion molecule-1 (VCAM-1). Immunohistochemical analysis was performed on biopsies taken from unchallenged skin, and at 0, 2, 6, 24, 48 and 120 h after weighted rods had been applied to 13 patients with DPU. There was moderate to marked upregulation of E-selectin at 6 and 24 h after application of pressure. At 24 h, more patients showed expression of VCAM-1 on perivascular cells than before pressure. Moderate expression of ICAM-1 was present in some biopsies from both unchallenged and pressure-challenged skin, but there was no clear trend. In DPU, there was a significant increase in the neutrophil count at 2 h after a pressure challenge, with further increases at 6 and 24 h. The median cell counts per high-power field of eosinophils and monocyte/ macrophages increased significantly at 24 h after pressure. Biopsies from four normal controls subjected to an identical pressure challenge showed no detectable changes in adhesion molecule expression or in the cell infiltrate. The findings in four patients with chronic idiopathic urticaria not associated with DPU were qualitatively similar to (but intermediate in severity between) the findings in DPU weals at 6 and 24 h. These results suggest that vascular endothelial activation is an early response to pressure challenge in DPU, and is also present in chronic idiopathic urticaria. The inflammatory infiltrate in DPU differs in intensity, but not in composition, from that in chronic idiopathic urticaria.

Previous studies have shown that scale from lesional psoriatic skin contains substantial amounts of platelet activating factor (PAF). In this study, PAF and its immediate precursor, lyso-PAF, were measured in exudates from abrasions on lesional and uninvolved psoriatic skin, and from skin of healthy subjects. The mean amounts of PAF recovered from lesional and uninvolved psoriatic skin (n = 13) and from healthy skin (n = 14) were not significantly different (range 0.05-2.14 pmol/sample). Mean recoveries of lyso-PAF from lesional psoriatic skin (n = 9) and skin of healthy subjects (n = 13) were also similar (9.5 +/- 1.9 and 11.0 +/- 1.9 pmol/sample, respectively), but significantly less lyso-PAF was found in exudates from the uninvolved psoriatic skin (n = 9; 3.1 +/- 0.4 pmol/sample; P0.01 relative to both lesional psoriasis and healthy skin). The finding of reduced lyso-PAF in uninvolved psoriatic skin was unexpected because increased phospholipase-A2 activity is associated with psoriasis. These results do not support the hypothesis that extracellular PAF contributes significantly to the inflammation associated with psoriasis.

1. Previous, in vitro, studies have established the synthesis of platelet activating factor (PAF) by the 're-modelling' pathways in which the activation of a phospholipase A2 (PLA2) enzyme catalyses the hydrolysis of an ether-acyl-phosphocholine to give concomitant release of lyso-PAF, the immediate precursor of PAF, and arachidonic acid, the precursor of the icosanoids. The aim of this study was to investigate the relationship between PAF and eicosanoid release in human skin, and to study the effect of treatment of skin with a topical steroid, on the release of PAF, lyso-PAF and arachidonic acid. 2. A novel assay procedure was developed for the simultaneous assay of PAF and lyso-PAF in skin exudates from abrasions and suction blisters in normal human skin. In addition we assayed arachidonic acid and prostaglandin E2 (PGE2), a representative eicosanoid. 3. The mean amounts of mediator recovered in the first 30 min period following abrasion were PAF 0.43, lyso-PAF 11.9, PGE2 25.7 and arachidonic acid 760 pmol/sample. The molar ratio of PAF:lyso-PAF:arachidonic acid in skin exudates from abrasions was 1:30:1800 and in suction blister exudates was 1:90:3660. 4. Time course studies showed a decline in the recoveries of arachidonic acid and lyso-PAF, of about 50% in 2 h. In contrast, PAF was recovered in exudates at a constant rate over 2 h but PGE2 release decreased by more than 90% after the initial 30 min period. 5. Topical application under occlusion, of 0.05% clobetasol propionate, a potent corticosteroid, significantly reduced lyso-PAF by 30% in suction blister exudates but did not significantly alter the concentrations of PAF or arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin 1 (IL-1) and interleukin 6 (IL-6) were measured by bioassays in suction-blister exudates from lesional skin, from skin immediately following a pressure challenge, and from control skin (not subjected to pressure) of patients with delayed pressure urticaria. IL-6 activity in lesional exudates was significantly higher than in exudates from the other two sites. IL-1 activity in lesional exudates was not significantly higher than in the control exudates, but significantly less IL-1 activity was found immediately after pressure challenge than from the control site.

This article reviews the effect of H1 antihistamines on the pruritus of urticaria, from articles in which their therapeutic effect on chronic idiopathic and physical urticaria is assessed. In limited studies available pruritus improved concomitantly with wealing by an average of two thirds, though the response in individual patients was variable. In some physical urticarias the pruritus and wealing showed disproportionate improvement compared to erythema. The minimally sedating H1 antihistamines were as effective or more effective than classical H1 antihistamines. The dose of antihistamines that totally abolished a histamine weal only partly reduced urticarial weals (therefore by inference also of the associated pruritus). Additional therapy aimed at pruritogenic mediators other than histamine would be expected to improve urticarial pruritus.

This report is based on a 2-day meeting held in Cambridge in January 1990. It picks out some of the recent advances since a previous meeging in 1984.1

SUMMARY The role of locally released cytokines in inducing lymphocyte activation and infiltration in the skin lesions of mycosis fungoides has been investigated. The levels of selected cytokines were measured in chamber fluid samples from lesional and control skin. Biologically active interleukin 6 was significantly elevated in lesional samples and a recombinant form of this cytokine was shown to induce lymphocyte migration in an in vitro assay. Biologically active interleukin 1 was detected in all control chamber fluid samples. Significantly reduced levels of this cytokine were present in lesional samples, which may be the result of the release of preformed material. Interleukin 2 and tumour necrosis factor activity, and γ interferon and granulocyte macrophage colony-stimulating factor immunoreactivity, were not detectable in any of the samples. Interleukins 1 and 6 may play a role in the pathogenesis of the lesional lymphocyte infiltrates in mycosis fungoides.

The pharmacologic and clinical effects of the 5-lipoxygenase inhibitor, lonapalene, have been determined in a double-blind, placebo-controlled, topical study in ten volunteers with psoriasis. A statistically significant clinical improvement was seen in lesions treated with 2% lonapalene ointment as compared with vehicle-treated sites. Although there was a statistically significant reduction in the levels of material similar or identical to the chemoattractant arachidonate 5-lipoxygenase product, leukotriene B4>, in skin chamber fluid samples from lonapalene versus vehicle treated lesions, no significant reduction in arachidonic acid or 12-hydroxy-5,8,10,14-eicosatetraenoic acid was seen. The reduction in leukotriene B4 equivalents occurred before significant clinical improvement in lesions was seen. This and the selectivity of the pharmacologic response suggest that the therapeutic effect of topical lonapalene in psoriasis might be related to inhibition of leukotriene B4 synthesis. These results support the view that 5-lipoxygenase inhibitors may be useful in the treatment of psoriasis, and that leukotriene B4 is a relevant mediator of the pathology of this disease.

The underlying pathophysiology of chronic urticaria is mast cell activation, with release of histamine and other mast cell mediators. A weal producing factor has been identified in the serum of 60% of patients with chronic idiopathic urticaria. In half of these patients there is evidence for functional autoantibodies against the high affinity IgE receptor or IgE, or both. These autoantibodies release histamine from basophils and mast cells. It is therefore likely that there is an autoimmune basis for up to 30% of patients with idiopathic urticaria. In the other half of patients whose serum causes weals, the factor releases histamine from mast cells only and is as yet unidentified. So far no clinical difference has been associated with presence/absence or type of weal producing factor. Exacerbating factors in chronic urticaria such as aspirin, food additives, febrile illness and psychological stress should be identified and avoided. Treatment is symptomatic with the low sedation antihistamines. In the most severe cases not responding to conventional therapy and which may have the weal producing factor, treatments with non specific immune therapy such as cyclosporin, and intravenous gammaglobulin and also plasmapheresis have been promising.

This investigation was carried out to compare the therapeutic efficacy and cosmetic acceptability of prednicarbate 0.25% ointment in the treatment of atopic dermatitis, and to monitor any local side-effects. A group of 51 patients suffering from atopic dermatitis were randomized to twice daily treatment with prednicarbate 0.25% ointment (n = 24) or vehicle control (n = 27) in a parallel group design with a 4-week treatment period. Prior to treatment, the groups were comparable in all clinically relevant aspects. Prednicarbate was shown to be statistically significantly superior to vehicle control in terms of efficacy. The number of adverse events was observed to be higher in the control group than in the prednicarbate group (15 and 2, respectively).

Adult Still's disease (ASD) is a rare disorder of unknown aetiology, characterized by an evanescent, erythematous, maculopapular rash, fever, arthralgia, and a variety of systemic features. We report a case which illustrates the typical features of ASD, and manifests the hitherto unreported complication of diffuse cutaneous mucinosis.

Background : Circulating autoantibodies against FcϵRI, IgE, or both occur in approximately one third of patients with chronic idiopathic urticaria (CIU), but not all autoantibodies initiate histamine release. Objective : We sought to classify patients with CIU into subsets on the basis of serum bioactivity and immunoreactivity and to examine the relationship between newly defined subtype and disease severity. Methods : Sera from patients with CIU (n = 78), dermog-raphism (n = 15), and cholinergic urticaria (n = 10) and sera from healthy subjects (n = 39) were analyzed by means of Western blot analysis for anti-FcϵRI autoantibodies and for histamine release from basophils and dermal mast cells. In vivo reactivity of autologous serum was tested by means of intradermal injection, and CIU severity was determined on the basis of clinical interview. Results : We classified sera from patients with CIU into 5 subsets: immunoreactive histamine-releasing anti-FcϵRI autoantibodies (n = 20 [26%]); immunoreactive anti-FcϵRI autoantibodies without histamine-releasing activity (n = 12 [15%]); anti-IgE-like autoantibodies (n = 7 [9%]); serum containing a mast cell-specific histamine-releasing factor (n = 7 [9%]); and sera with no identifiable factor (n = 32 [41%]). Patients with serum histamine-releasing activity had more severe urticaria than patients without such activity. Positive skin test responses to autologous sera were associated with histamine-releasing anti-FcϵRI autoantibodies but not with non-histamine-releasing anti-FcϵRI autoantibodies. Neither healthy subjects nor patients with dermographism or cholinergic urticaria had his-tamine-releasing anti-FcϵRI autoantibodies. Conclusion : These data support the specificity of functional anti-FcϵRI autoantibodies to CIU. The identification of distinctive subsets of patients suggests that other pathogenic mechanisms occur in CIU in addition to direct ligation of FcϵRI by autoantibodies causing dermal mast cell degranulation. Elucidating these mechanisms might lead to new treatments for CIU. (J Allergy Clin Immunol 2002;110:492-9.)

H1-antihistamines are the cornerstone of symptomatic treatment in acute and chronic urticaria, in which they not only relieve itching, but also reduce the number, size, and duration of urticarial lesions. Relief of whealing, flaring, and erythema may be incomplete as the vascular effects of histamine are mediated to its action at H2-receptors as well as at H1-receptors, and other vasoactive substances may also be involved. In randomized, prospective, placebo-controlled, double-blind studies, the new low-sedating H1-antihistamines have been found to be effective and safe in urticaria. Sedating antihistamines, although effective, place patients at risk for adverse effects, including decreased psychomotor performance. The response to H1-antihistamines in some types of urticaria, for example, in urticarial vasculitis, is unsatisfactory. An H2-antihistamine administered concurrently with an H1-antihistamine may modestly enhance relief of itching and wheal formation in some patients with urticaria refractory to treatment with an H1-antihistamine alone. The available evidence does not justify the routine addition of H2-antihistamine treatment to H1-antihistamine treatment.

H1-antihistamines are the cornerstone of symptomatic treatment in acute and chronic urticaria, in which they not only relieve itching, but also reduce the number, size, and duration of urticarial lesions. Relief of whealing, flaring, and erythema may be incomplete as the vascular effects of histamine are mediated to its action at H2-receptors as well as at H1-receptors, and other vasoactive substances may also be involved. In randomized, prospective, placebo-controlled, double-blind studies, the new low-sedating H1-antihistamines have been found to be effective and safe in urticaria. Sedating antihistamines, although effective, place patients at risk for adverse effects, including decreased psychomotor performance. The response to H1-antihistamines in some types of urticaria, for example, in urticarial vasculitis, is unsatisfactory. An H2-antihistamine administered concurrently with an H1-antihistamine may modestly enhance relief of itching and wheal formation in some patients with urticaria refractory to treatment with an H1-antihistamine alone. The available evidence does not justify the routine addition of H2-antihistamine treatment to H1-antihistamine treatment.

Urticaria is a well-known disease entity; however, with an increasing understanding of the molecular mechanisms involved in its pathogenesis, there is also growing evidence for a heterogeneity of urticaria. Currently it is sometimes difficult to compare divergent data reported by different centers researching urticaria due to a lack of precisely described patient populations. A consensus definition and classification of the disease and its subtypes, taking into account new developments, are therefore needed. In addition, this consensus report provides a guideline for diagnostic procedures in different subtypes of urticaria.

A patient with atypical Nekam's disease is described. Although the histological appearances were lichenoid, the presence of porokeratosis and amyloid deposition, previously reported in this condition, argue against the view that Nekam's disease is a subset of lichen planus.