text: i have rashes appearing on my body very frquently? i take a daily dose of cetizne.is it harmful  please help me there are hundreds of different types of rashes, and even more possibly causes. it could be a symptom of something else, or it could be a disease all its own. could be an allergy, could be a fungal or yeast infection, could be idiopathic (no known cause). without a description of what the rash looks like, no one can tell you what it is. see a doctor.  i assume you mean the drug cetirizine, which is the antihistamine commonly known as zyrtec. many people, myself included, use antihistamines daily on a long term basis, without any ill effect.