Chronic urticaria is a common clinical disorder that is idiopathic in over 75% of cases. Less commonly,
urticaria may be the presenting manifestation of an allergic or
infectious disease, endocrinopathy, inherited syndrome, or autoimmune disorder. Rarely,
urticaria may be a sign of underlying
malignancy, including
leukemia. C.C. is a 48-year-old white female who was referred for evaluation of recurrent
urticaria for 3 years. The pruritic, erythematous wheals were pinpoint, and appeared to be precipitated by heat, stress, and effort. Prick tests were negative except to D. pteronyssinus. CBCs over the past 5 years revealed WBCs of 2,300-5,000 cells/mm3. Skin biopsy revealed interstitial
edema with infiltration of eosinophils and mast cells consistent with
urticaria. The impression was probable
cholinergic urticaria, for which
hydroxyzine was prescribed with fair symptomatic control. One year later, she presented with bright red blood per rectum. Repeat physical examination revealed
lymphadenopathy and
splenomegaly. Subsequent laboratory studies showed
pancytopenia. Endoscopy was normal except for small, nonbleeding
hemorrhoids. Bone marrow biopsy revealed histologic evidence of hair, cell
leukemia that was treated with
2-chlorodeoxyadenosine. Upon initiation of
chemotherapy her
pruritus and
urticaria subsided. Recent CBC revealed Hgb 9.2 g/dL, platelets 290,000 cells/mm3, and WBC 4,100 cells/mm3. Peripheral blood smear showed no hairy cells.