It might be a boil... Main reason for this is heat in the gaster(stomach)...... Natural way out for this is to increase water intake to control that heat.....
Next Steps
Next Step what you can do for the one which is bothering you right now is either ripening it so that it bursts open on its own Or if it's a new and younger ones can be made to get dried up from within.
Health Tips
Only homoeopathy can do that, but i need to take your acute case to prescribe you a medicine.