Hi. Thanks for your query. Noted the history and understood the concerns. Swelling of the finger while working with plants could be due to two reasons: Crushing trauma that can cause this. Minor cut that could not be noticed while working is now getting infected. Since there is spread of redness and swelling, this should taken as due to infection and hence I would advise you the following in such a situation: Get an antibiotic cover to avoid further infection as you have already opened up the blister. Blister when intact acts as a dressing not allowing the outside bacterial attack and thus does not allow infection to occur. Locally liquid povidone iodine. Consult your Doctor for evaluation, dressing, injection tetanus toxoid and medications as required. Remember to keep the affected part elevated above heart level.