2021 Volume 20 Issue 1 Pages 6-10
A 78-year-old Japanese woman was diagnosed with anaphylactic shock due to loss of consciousness, hypotension, and generalized edematous erythema. She was referred to our hospital after treatment for the shock. She was febrile, and edematous erythemas were widely distributed on her trunk and extremities. Blood examination revealed a slightly elevated white blood cell count and C-reactive protein. The plasma D-dimer level was significantly elevated (30.6 μg/mL ; normal range ＜0.9 μg/mL). Histological examination showed superficial dermal edema and perivascular infiltration, mainly composed of lymphocytes, neutrophils, and eosinophils around the dermal blood vessels. Leukocytoclastic vasculitis was not observed. Antihistaminic treatment was unsuccessful. Antibiotic treatment was empirically started without an obvious focus of infection as the proposed diagnostic criterion of acute infectious urticaria was met, after which her fever and eruption were resolved. The plasma D-dimer level was also almost normalized. Systemic workup failed to identify other potential causes of the anaphylactic shock and elevated plasma D-dimer level. Thus,we diagnosed the case as acute infectious urticaria complicated with anaphylactic shock. Some reports, including ours, showed that acute infectious urticaria may cause anaphylaxis. We also speculated that the elevation of the plasma D-dimer level was related to urticaria. Considering recent studies on the relationship between urticaria and the coagulation system, the plasma D-dimer level may be significantly elevated in acute infectious urticaria. Skin Research, 20 : 6-10, 2021
