Ultra-freeze induced cold contact wheals during cryosurgery: an uncommon subset of acquired cold contact urticaria.

UNLABELLED: Cryosurgery is a safe and effective therapeutic tool for a wide variety of cutaneous and mucocutaneous disorders. Side-effects include transient erythema and oedema. OBJECTIVE: A series of three patients presenting localized contact wheals minutes after contact with liquid nitrogen in the absence of clinical manifestations of cold urticaria is presented. METHODS: Specific cold diagnostic provocation tests with liquid nitrogen challenge test, ice cube test and Tempt-test® were performed. RESULTS: The three patients showed an immediate wheal after cold contact with liquid nitrogen. The ice cube test, the temperature thresholds and the critical stimulation thresholds at 4◦C assessed with the Tempt-test 3.1® were negative. The induced wheals showed pathological features of urticaria. Eight patients suffering from acquired cold urticarial developed also liquid nitrogen induced wheals but none of the healthy controls. CONCLUSION: A peculiar subset of cold urticaria secondary to exposure to ultra-freeze temperatures developing in patients treated with cryotherapy is reported. The concept of "ultra-freeze urticaria" is proposed.

Streptococcus induces circulating CLA(+) memory T-cell-dependent epidermal cell activation in psoriasis.

Streptococcal throat infection is associated with a specific variant of psoriasis and with HLA-Cw6 expression. In this study, activation of circulating psoriatic cutaneous lymphocyte-associated antigen (CLA)(+) memory T cells cultured together with epidermal cells occurred only when streptococcal throat extracts were added. This triggered the production of Th1, Th17, and Th22 cytokines, as well as epidermal cell mediators (CXCL8, CXCL9, CXCL10, and CXCL11). Streptococcal extracts (SEs) did not induce any activation with either CLA(-) cells or memory T cells cultured together with epidermal cells from healthy subjects. Intradermal injection of activated culture supernatants into mouse skin induced epidermal hyperplasia. SEs also induced activation when we used epidermal cells from nonlesional skin of psoriatic patients with CLA(+) memory T cells. Significant correlations were found between SE induced upregulation of mRNA expression for ifn-γ, il-17, il-22, ip-10, and serum level of antistreptolysin O in psoriatic patients. This study demonstrates the direct involvement of streptococcal infection in pathological mechanisms of psoriasis, such as IL-17 production and epidermal cell activation.