%0 Journal Article %T Autologous Serum Skin Test versus Autologous Plasma Skin Test in Patients with Chronic Spontaneous Urticaria %A Aysegul Alpay %A Nilg¨¹n Solak Tekin %A Ishak £¿zel Tekin %A H. Cevdet Altinyazar %A Rafet Koca %A Saniye £¿£¿nar %J Dermatology Research and Practice %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/267278 %X Previous studies indicate that 25¨C45% of chronic urticaria patients have an autoimmune etiology. Autologous serum skin test (ASST) and autologous plasma skin test (APST) are simple tests for diagnosing chronic autoimmune urticaria (CAU). However, there are still some questions about the specificity of these tests. This study consisted of 50 patients with chronic spontaneous urticaria (CSU) and 50 sex- and age-matched healthy individuals aged 18 years, and older. A total of 31 (62%) patients and 5 (10%) control patients had positive ASST; 21 (42%) patients and 3 (6%) control patients had positive APST. Statistically significant differences were noted in ASST and APST positivity between the patient and control groups (ASST ; APST ). Thirteen (26%) patients and 5 (10%) control patients had antithyroglobulin antibodies or antithyroid peroxidase antibody positivity. No statistically significant differences were noted in thyroid autoantibodies between the patient and control groups (anti-TG ; anti-TPO ). We consider that the ASST and APST can both be used as in vivo tests for the assessment of autoimmunity in the etiology of CSU and that thyroid autoantibodies should be checked even when thyroid function tests reveal normal results in patients with CSU. 1. Introduction Chronic spontaneous urticaria is a skin disorder which follows a course with erythematous, edematous, and itchy plaques, almost daily, for over 6 weeks and which is associated with lower quality of life affecting work and daily activities of patients [1, 2]. The most important causes of chronic spontaneous urticaria include chronic infections, food intolerance, chronic noninfectious inflammatory diseases (gastritis, esophagitis, etc.), and atopy [3]. No apparent cause is identifiable in approximately 70% of patients [4¨C7]. This patient group, termed chronic idiopathic urticaria, is subdivided into ¡°chronic autoimmune urticaria (CAU)¡± and ¡°chronic spontaneous urticaria (CSU)¡±, and CAU accounts for 25% of patients with chronic urticaria [6, 8]. There is sound evidence indicating the presence of functional histamine releasing autoantibodies or nonantibody factors (serum factor) against the ¦Á subunit (Fc¦ÅRI¦Á) of IgE or the high affinity IgE receptors from basophil and mast cells in patients with CAU [5, 6, 9¨C11]. The presence of these autoantibodies is demonstrated by papular and erythematous reaction by intradermal injection of autologous serum or autologous plasma (autologous serum skin test (ASST); autologous plasma skin test (APST)) [12¨C14]. ASST is an in vivo test used for the diagnosis of %U http://www.hindawi.com/journals/drp/2013/267278/