Diagnosis and incidence of delayed pressure urticaria in patients with chronic urticaria

Chronic urticaria

Chronic urticaria remains a major problem in terms of etiology, investigation, and management. It is important to identify patients in whom physical urticaria is the principal cause of disability. Once confirmed by appropriate challenge testing, no further investigation is required. Urticarial vasculitis (UV) is a major differential diagnosis of "idiopathic" urticaria (CIU). I perform biopsy of most patients in this category because UV cannot be considered confirmed in the absence of histologic evidence. Patients with confirmed UV need to be thoroughly investigated for paraproteins, lupus erythematosus hepatitis B and C, and inflammatory bowel disease. Of patients with CIU, a few (<5%) prove to have food additive reactivity confirmed by placebo-controlled challenge testing. There is no convincing evidence of the involvement of Helicobacter pylori or parasite infestation as a cause of chronic urticaria, although H pylori could have an indirect role. Recently it has become clear that 27% to 50% of patients with CIU have functional autoantibodies directed against the alpha-chain of the high-affinity IgE receptor or less commonly against IgG. These antibodies, whose involvement has now been independently confirmed in several centers, are identified by autologous serum skin testing and confirmed by histamine release studies or immunoblotting. Their removal (by intravenous Ig or plasmapheresis) or treatment by cyclosporine has proved highly beneficial in severely affected patients. However, the routine treatment of all CIU patients, irrespective of etiology, remains the judicious use of H(1) antihistamines.

Human leucocyte antigen class II associations in chronic idiopathic urticaria

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.

Cutaneous inflammatory cell infiltrate in chronic idiopathic urticaria: comparison of patients with and without anti-FcepsilonRI or anti-IgE autoantibodies

BACKGROUND

Previous studies defining the histopathologic features of patients with chronic idiopathic urticaria (CIU) were performed on wheals of uncertain duration and before the identification of functional autoantibodies against FcepsilonRI and/or IgE, now known to be present in approximately 30% of patients with CIU.

OBJECTIVE

We sought to determine the timing of the inflammatory infiltrate in the wheals of patients with CIU and to detect differences between patients with and without autoantibodies.

METHODS

Immunohistochemistry was used to identify neutrophils (neutrophil elastase), T lymphocytes (CD3), and activated eosinophils (EG2) in biopsy specimens from uninvolved skin and wheals present for less than 4 hours and greater than 12 hours in 22 patients with CIU, as well as in biopsy specimens from the skin of 12 healthy control subjects. Patients were identified as having functional autoantibodies on the basis of their serum-evoked histamine release in vitro from the basophils of 2 healthy donors.

RESULTS

EG2(+), neutrophil elastase+, and, to a lesser extent, CD3(+) cells were found in greater numbers in wheals undergoing biopsy at less than 4 and greater than 12 hours than in uninvolved skin (P <.05). Patients without autoantibodies (n = 12) had significantly more EG2(+) cells in wheals of greater than 12 hours' duration than patients with autoantibodies (n = 10; P =.02). There was no other difference between patients with and without autoantibodies in the cutaneous cellular infiltrate.

CONCLUSION

Neutrophil and eosinophil accumulation occurs early in the evolution of a wheal in patients with CIU, but eosinophil activation may occur later or be more persistent in patients without autoantibodies.

Chronic idiopathic urticaria: comparison of the clinical features of patients with and without anti-FcepsilonRI or anti-IgE autoantibodies

BACKGROUND

Previous studies defining the clinical features of patients with chronic idiopathic urticaria (CIU) were performed before the identification of functional autoantibodies against FcepsilonRI 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 < .0005) than patients without autoantibodies.

CONCLUSION

The presence of autoantibodies indicates a subset of patients with more severe CIU.

Urticaria, angioedema, and rheumatologic disease

Urticaria and angioedema are common processes that are experienced by 15% to 25% of the population at least once during a lifetime. This article presents an overview of urticaria and angioedema with emphasis on these processes as they relate to rheumatic disease. Discussion includes classification of urticaria and angioedema and recommended evaluation and treatment of patients presenting with such problems.

Adhesion molecule expression and the inflammatory cell infiltrate in delayed pressure urticaria

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.(ABSTRACT TRUNCATED AT 250 WORDS)