Autologous serum skin test and autologous whole blood injections to patients with chronic urticaria: A retrospective analysis

Background: Chronic urticaria (CU) is defined as widespread short-lived (< 24 h) itching maculopapular skin lesions with or without angioedema for more than 6 weeks for which a predominant physical cause must be excluded. The autologous serum skin test (ASST) has been shown to result in immediate hypersensitivity-type skin reactions in a subpopulation of CU patients and autologous whole blood (AWB) injection has been used as one of treatment modalities. Objective: To evaluate the relationship of a panel of laboratory examinations to the positivity of ASST and to evaluate the efficacy of AWB injection in the treatment of ASST (+) and ASST (-) CU patients. Methods: A retrospective chart review was performed on CU patients who were subjected to ASST and received AWB injection therapy. We assessed the therapeutic effects of 8 weekly AWB injections in ASST (+) and ASST (-) CU patients by using urticaria activity score (UAS). Results: Thiry-seven patients were analysed. There was no significant differences in number of patients, sex distribution, age, smoking vs. non-smoking, exacerbation of uricarial symptoms due to stress, and UAS between ASST (+) and ASST (-) CU patients at baseline. All patients presented normal complete blood count/differential count, and ANA. Anti-microsomal antibody was positive in 3/15 (20.0%) ASST (+) patients and in 2/22 (9.0%) ASST (-) patients (P = 0.6). The 8-week course of AWB injection was well tolerated. ASST (+) patients, but not ASST (-) patients, showed significantly reduced CU activity. Conclusion: 8 of the 9 ASST (+) patients with CU responded to treatment with AWB injection. Only 2 of the 8 ASST (-) patients showed response to the treatment. Others were having no effects or exacerbation of the urticarial symptoms. Further studies utilizing larger number of patients, longer follow-up periods, and different amount of autologous serum injection may better define the clinical efficacy of autologous serum injection for the treatment of chronic urticaria with positive ASST.