<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi I thought I got bitten by an insect but my arm swole up so I could not bend it. I had around 20 largish blisters around the area. Is there a weed that may have caused this, there were stinging nettles there that pricked my other arm but that was fine after a few hours.  <response>: Cellophane You for contacting Chat Doctor. These symptoms are due to allergic response from the insect bite or weed plant. I would suggest you following : Take levocetirizine one at night for allergy Try to avoid touching the plant. Avoid touching the bitten area with dirty hands. take a piece of cloth, warm over flame and then place over swelled area. IT will give soothing effect. take acetaminophen for pain if occursReport to hospital if: Condition remain same after 2-3 days Any unusual symptom appears Condition deteriorates. There is difficulty in breathing. Hope this answers your question. If you have additional questions or follow-up questions then please do not hesitate in writing to us. Wishing you good health. 