One of the proposed mechanisms in CU is autoimmunity. It was shown by a positive response to autologous serum skin test (ASST)in almost half of chronic urticaria (CU) patients. IL-18 also play a role in autoimmune disorders. The investigators aim was to investigate the relationship of ASST and IL-18 in CU and respiratory allergic diseases.

Inclusion Criteria:

• adult patients
• chronic urticaria patients
• stable asthma patients
• allergic rhinitis patients with sensitized to pollens
• normal controls without atopic and skin disease.

Exclusion Criteria:

• unwillingness to the study
• other dermatological problems that could affect the skin test
• use of antihistamine drugs

patients from Outpatient clinic