Cellulitis is a potentially life-threatening bacterial infection that can develop through cracks or breaks in the surface of the skin. Strep (Streptococcus) and staph (Staphylococcus) bacteria are common causes of this disorder.
Cellulitis triggered by Staphylococcus aureus usually affects localized areas of skin, according to the Merck Manuals Online Medical Library (MMOML). Typically, it is associated with cutaneous (skin) abscesses and open wounds.
Cellulitis triggered by Streptococcus pyogenes usually affects larger areas of skin and may spread rapidly, notes the MMOML. This tendency stems from the bacteria's ability to damage cell structures that normally limit inflammatory reactions.
The MMOML and the Mayo Clinic note that Staphylococcus-related cellulitis may display resistance to common cellulitis treatments.
The MMOML and the Mayo Clinic report common potential symptoms for both forms of cellulitis. These include pain, tenderness, redness, swelling, skin warmth, fever and the appearance of small red spots or blisters.
The MMOML reports additional potential sources of cellulitis infection that include Pseudomonas aeruginosa, group B streptococci such as S. agalactiae and gram-negative bacilli such as Haemophilus influenzae.