Chronic idiopathic urticaria: profiles of skin mast cell histamine release during active disease and remission.

Chronic idiopathic urticaria (CIU) is characterized by the increased releasability of histamine by mast cells in normal-appearing skin. In active CIU, this abnormality is consistently present. To determine if this finding subsides when the disease goes into remission phase, we analyzed the histamine secretion in patients with CIU in remission (CIUR) compared with that of patients with CIU and in normal control (NC) subjects, with the skin-chamber technique. The profiles of histamine release in sites challenged with compound 48/80 were significantly different in the groups with CIU and CIUR. Furthermore, patients with CIUR did not differ from NC subjects in terms of histamine releasability under compound 48/80 stimulation (p greater than 0.1). These data suggest that the state of excessive skin mast cell sensitivity is a reversible and transient phenomenon in CIU disease.