How do you know that it is cellulitis, is it diagnosed?Cellulitis and erysipelas are diffuse spreading skin infections not associated with underlying suppurative foci.Erysipelas is differentiated from cellulitis by the depth of inflammation; erysipelas affects the upper dermis, including the superficial lymphatics, whereas cellulitis affects the deeper dermis and subcutaneous fat.first thing u need do is consult to a specialist