<s>[INST] hi.. I hv an allergy tht gets on my whole body when there is a cool weather or when i m sitting in an AC room. when a mosquito bites, skin protrudes a little bit, like that only i hv allergy on my whole body. itching is also there. i m sufferng from this allergy from past 5 yrs. i also took the homopathic tratement bt its all in vain. i also take allegra tablet smetimes. plz help me. i m 20 yrs old n my height is 57. my weight is 54kg. [/INST] Hello. Thank you for asking at Chat Doctor. I went through your history. From your history, I can think of 3 possibilities: 1. Cold temperature itself causes your symptoms.2. Sudden temperature change from warm to cold temperature causes your symptoms.3. You may have sweating, and when it gets exposed to cold temperature, it causes your symptoms. I would suggest you to think above possibilities and try to identify exactly what causes allergic reaction. All these may be part of physical urticaria syn Chat Doctor. For treatment, I would make following suggestions:1. You can take antihistamines like Allegra (which you are already taking) when you are getting symptoms.2. Avoid activities which cause excessive sweating.3. Please avoid tight-fitting or woolen clothing. Loose fitting, cotton clothing is best.4. If you think you have  </s>