Thanks for the query. Keloid is a difficult medical condition to treat completely. The most common reason to have keloid is after a skin trauma and the risk increases many-folds if other family members are affected (strong genetic tendency). Intralesional drugs are commonly used by dermatologists all over to treat keloids. Most of the time, it requires multiple sessions and we aexpect atleast 50-70 % improvement in terms of flattening and minimizing itch. If there is a sudden pain and swelling, it may indicate an infection. You need to consult a dermatologist for the needful. The expert will decide if your present condition will merit with usage of an antibiotic. Apart from active pharmaceutical medicines, a healthy diet and lifestyle is mandatory to achieve results.   Best wishes Dr MK Agarwala