Delayed pressure urticaria, objective evaluation of a variable disease using a dermographometer and assessment of treatment using colchicine

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

BACKGROUND

The incidence of delayed pressure urticaria (DPU) may have been underestimated, particularly in patients with widespread wheals of concurrent idiopathic urticaria, because of difficulty in recognizing the association between pressure-related swellings and the preceding physical stimulus. Diagnostic tests for DPU have not been done routinely in studies of urticaria and have not been compared.

OBJECTIVE

Our purpose was to establish the incidence of DPU and other physical urticarias in patients with chronic urticaria and to compare two reproducible pressure challenge tests.

METHODS

One hundred thirty-five patients were tested for immediate dermographism, for DPU and, when indicated by the history, for cholinergic and/or cold urticaria. In patients with pressure-related symptoms, pressure challenge testing with a dermographometer (100 gm/mm2) was compared with a test that involves the application of 1.5 cm diameter weighted rods and more closely resembles a naturally occurring pressure stimulus.

RESULTS

Physical urticarias were present in 96 patients (71%). Thirty patients (22%) had immediate dermographism, 50 (37%) had DPU, 15 (11%) had cholinergic urticaria, and 3 (2%) had cold urticaria. A 70-second pressure challenge with the dermographometer gave results comparable to the use of the weighted rods.

CONCLUSION

DPU appears to be more common in chronic urticaria than previously reported and is present in some patients who do not report pressure-related wheals.

Increased interleukin 6, but reduced interleukin 1, in delayed pressure urticaria

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.

Acute and chronic urticaria and angioedema

Urticaria and angioedema are clinical manifestations of various immunologic and inflammatory mechanisms, or they may be idiopathic. The respiratory and gastrointestinal tracts as well as the cardiovascular system may be involved in any combination. Patients with urticaria and/or angioedema can be classified based on pathophysiologic mechanisms into those with IgE-dependent or complement-mediated immunologic disorders, those with nonimmunologic disorders in which there is a direct effect on the mast cell or on arachidonic acid metabolism, and those whose condition is idiopathic. Evaluation of patients should focus on a thorough history. Laboratory tests provide minimal additional information. About one half of patients with urticaria alone and 25% with urticaria and angioedema or angioedema alone are free of lesions within 1 year. With urticaria, angioedema, or both, 20% of patients experience episodes for more than 20 years.

Arachidonic acid transformation is not stimulated in delayed pressure urticaria

Little is known about the molecular mechanisms or inflammatory mediators involved in delayed pressure urticaria (DPU). Pressure sufficient to provoke lesions was applied to the back of six patients with DPU. The levels of products of arachidonic acid transformation in skin exudate from the pressure challenged skin were estimated immediately after pressure was removed and 6 h later when lesions were present. These were compared to levels estimated in a similar way from unchallenged skin in these patients. Levels of leukotriene C4/D4/E4, prostaglandin E2, 12-hydroxyeicosatetraenoic acid and leukotriene B4 were not raised in lesional skin. Our results suggest that arachidonic acid metabolism is not stimulated in DPU.