Q: I am a 28 years old female and getting rashes since 2 years. These rashes appear once in a day or two and stay for 3 to 4 hours. The doctor told me that it's allergic rash. But I never had this problem (allergy) till I was 26 years. I am unable to identify the reason for the allergy. My doctor is asking me check on what I eat everyday. I am not eating anything different from what I was having during the last 26 years. My doctor has prescribed me Cetirizine. Does it have side effects? Are there any other reasons for this?

A:Allergies are a result of previous exposure, so the fact that a patient has previously tolerated anything, whether a food or an environmental allergen such as pollen, is quite consistent with an allergy developing. This is generally more likely when young, but can occur at any age. If the rash can appear when you haven’t eaten for a couple of hours, it is unlikely to be due to food allergy. Many patients have rashes, which do not have an allergic origin, e.g. idiopathic urticaria. Cetirizine is a safe and usually effective antihistamine; other alternatives include fexofenadine, loratadine or acrivastine. A few tests to rule out thyroid disease, intestinal parasites and autoimmune disease such as lupus are probably advisable. Most patients with idiopathic urticaria recover in a few years, but some take longer.( I am guessing that this is the nature of your rash).