Hi der,
After going through your concern,I'm assuming that you are having localised
cellulitis not throughout the arm.Correct me if I'm wrong . Cellulitis is a painful condition and its treatment takes lil time.So you need to be patient.As mentioned by you,you are on antibiotics and that the
rash has cleared around the site.Its a good sign that the antibiotics are working.
My advice would be to
1 Please continue the antibiotics as prescribed to you.
2 Avoid scratching the area or touching it often as it may result in secondary infection.
3 Wear loose clothing around it and try to keep it dry.
If you continue the prescribed treatment by your doctor,the cellulitis should subside.
As for your second concern that if you go to ER will they lance it?Well for this the answer is no.Cellulitis is treated with antibiotics till it subsides.It doesn't require any surgical removal . It is inflammation of skin and tissue beneath it and as you described here, there seems to be no infection around.Its best left untouched and wait for the antibiotics to do their work.All you need is lil patience and compliance to complete the course prescribed.
Wishing you a speedy recovery.