It seems like many SDS folks get cellulitis. We've dealt with it 9 or 10 times now and have had to be hospitalized for it. My boys have a chemotaxis defect as well as neutropenia. J developed cellulitis even with G-CSF and GM-CSF. Only one time did we have a fever with cellulitis...and with SDS, my boys did nothave a huge white blood cell count increase.
We have learned a lot over the years. We've had cellulitis on the toes, knees, surgery sites, injection sites and private areas. If possible, we circle the area with ink (pen) and watch to see if the redness is spreading. We've only had pus develop once and had to have it drained. People with neutropenia don't always have a fever response or develop pus because of lack of neutrophils. In my boys' case, they mounted a response, not a huge WBC, but bcause of neutrophil chemotaxis problems, there was no pus. Doctors tried to culture the wounds, but we've never had much to culture because of lack of pus!
These are a few good articles on cellulitis that also include pictures.
MedicineNet Cellulitis article
Mayo Clinic Cellulitis article
eMedicine Cellulitis article
Cellulitis on Healthline
U of M Cellulitis article