Eligibility Criteria:
Inclusion Criteria:
* Adult ( \> 18 years of age)
* Outpatients with CCU for more than six weeks. Urticaria symptoms must comprise wheal and itch and be resistant to conventional antihistamine treatment in standard doses
* Patients with a positive cold stimulation test at 4°C (assessed by TEMPtest 3.0)
* Informed consent signed and dated. Able to read, understand and willing to sign the informed consent form
* Able to read, understand and complete study-related questionnaires
* Willing, committed and able to return for all clinic visits and complete all study-related procedures, including willingness to self-administer SC injections or to have SC injections administered by a qualified person
* In women, negative pregnancy test
* Reliable method of contraception for both women of childbearing potential as well as men, during the course of the study. A highly effective method of birth control is defined as those which result in a low failure rate (i.e. less than 1% per year) when used consistently and correctly such as implants, injectables, combined oral contraceptives, some IUDs, sexual abstinence or vasectomised partner.
* Subjects are considered eligible according to the following tuberculosis (TB) screening criteria:
* No history of latent or active TB prior to screening
* No signs or symptoms suggestive of active TB
* No recent close contacts with a person with active TB
* A negative QuantiFERON-TB test on day -14 (screening visit).
Exclusion Criteria:
* Treatment with a live (attenuated) virus vaccine during the month prior to day 0 (Randomization).
* A history of serious chronic or active infection(s) eg. listeriosis within six weeks prior to the screening visit.
* Evidence of acute or latent Tuberculosis as defined by the local guidelines/local medical practice
* A history of acute tuberculosis despite the proper treatment.
* Significant concomitant illness such as, but not limited to, cardiac, renal, neurological, endocrinological, metabolic, lymphatic or hematological disease that would adversely affect the subject's participation or evaluation in this study.
* Active systemic inflammatory condition including, but not limited to, rheumatoid arthritis, systemic lupus erythematosis, polymyalgia rheumatica, vasculitis, or myositis.
* History of fibromyalgia or chronic fatigue syndrome.
* Evidence of current HIV, Hepatitis B, or Hepatitis C infection by clinical or serological history.
* History of malignancies including malignant hematological disorders other than a successfully treated non-metastatic cutaneous, basal, or squamous cell carcinoma and/or in situ cervical cancer within five years of the Screening visit.
* Severe respiratory disease, including, but not limited to severe bronchiectasis, chronic obstructive pulmonary disease, bullous lung disease, uncontrolled asthma, or pulmonary fibrosis.
* Presence of any of the following laboratory abnormalities at enrollment visit: creatinine \>1.5 x Upper Limit of Normal (ULN), WBC \<3.6 x 103/mm3; platelet count \<150,000 mm3; ALT or AST \>2.0 x ULN.
* Previous ineffective treatment with IL1 inhibitor or other biologic agent.
* Known hypersensitivity to CHO cell derived therapeutics or proteins or any components of rilonacept.
* Any medical condition which, in the opinion of the Investigator, would interfere with participation in the study or place the subject at risk.
* Present History of substance abuse (drug or alcohol) or any other factor (e.g., serious psychiatric condition) that could limit the subject's ability to comply with study procedures.
* Lactating females or pregnant females.
* Enrollment in another investigational treatment or device study or use of an investigational agent, or no completion of less than 4 weeks or 5 half-lives, whichever is longer, since end of another investigational device or drug trial.
* Subjects for whom there is concern about compliance with the protocol procedures.
* Subjects who are detained officially or legally to an official institute.