Why is the skin allergic when it is cold?

Cold urticaria, to be exact. If the allergy caused by cold weather is mostly cold urticaria, it may be accompanied by fever, chills, headache and joint pain. Neutrophils increased, and passive transfer test was negative. The latter is more common in young women. After catching a cold, wheal or patchy edema appears in the contact or exposed parts for 30 minutes or several hours. Sometimes eating cold drinks can cause edema in the mouth and throat, and the passive transfer test is positive.

Acquired cold urticaria is related to the patient's personal constitution. For example, patients stay up late, fatigue leads to low immunity, or some diseases lead to decreased immunity.