Possible Injection Infection?

[s_c_a_l_e_s]

My most beloved Retic, Sonny, has just been given the clear from our vet to be taken off Baytril injections, after enduring a month of them to cure his rhespiratory infection.
Now, three of (what I assume) the injection sites are red and irritated, one especially capturing my concern. The first two have turned the yellow scales around the area almost completely white and raised his skin, while the third and most tender one has turned red and somewhat scabby.
I cannot add images as I'm on my iPhone, but if you have access to instagram, my account name is s_c_a_l_e_s, and you can see the images there.
The most irritated area is soft, and when I applied pressure to it, the raised bump flattened out. Do you think it would need to be drained?