Delayed pressure urticaria inhibition of induced lesions by adrenaline

1365-2230

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Two patients with delayed pressure urticaria were studied to define some of the physical and pharmaceutical parameters related to the lesions. Skin tests were performed with a pressure testing; device. Graded pressures were applied from 175 g/cm2 upward for several periods of time to the forearm and back. Induced lesions were clinically identical to spontaneous lesions. The threshold response was related to the amount of pressure, the duration of application and the body site tested. Induced lesions were followed by a refractory period of at least 2 h and up to 48 h. During this period, repeated challenges to an area that reacted previously did not produce any lesion, and, on the contrary, prolonged the refractory period. Any type of intradermal injection (NaCl, lidocaine, compound 48/80, histamine) induced a delayed reaction. But induced delayed lesions were inhibited by intradermal injection of adrenaline before, or after, the pressure stimulus. It is suggested that some intracutaneous targets react to external or intradermal pressure and release chemotactic factors, the effects of which are prevented by vasoconstriction.

Electronic Resource