• Foot infections in diabetes often begin around the toe nail bed (paronychia), around cracks in the skin of the foot, or arise from neuropathic or ischaemic ulcers.
• Infections are usually the consequence and not the cause of foot ulcerations. They can be divided into superficial (local), soft tissue and spreading (cellulitis) and osteomyelitis .
• Since, as mentioned earlier, the mere presence of bacteria does not necessarily define infection, an infection needs to be defined clinically .
• It is most typically manifested by signs and symptoms of inflammation, including induration, erythema, warmth, pain, tenderness or purulence.
• The clinical manifestations vary, according to the extent and depth of bacterial invasion, and to some degree according to the pathogen(s).
• The chronicity of the infection also plays a role: acute infections are usually associated with more prominent inflammatory findings, whereas chronic infections are usually not.
• Patients with ischaemia or neuropathy may have less prominent (or even absent) symptoms of an infection, due to their loss of pain perception and/or reduced blood flow.
• Clinical features of cellulitis are usually present as an early manifestation of a foot infection.
• Cellulitis is a soft tissue infection marked by erythema, warmth and swelling over the involved area (Fig. 8.1.4). Later the infection may spread to deeper tissues and it may be possible to express pus from a sinus tract or from an ulcer. As infection spreads deeper, soft tissue fluctuance may be present.
• Cutaneous bullae, soft tissue gas (with crepitus) or purple/black discoloration of the skin may occur in necrotizing infections (gangrene).
• Osteomyelitis may result from contiguous spread of the infection to the underlying bone(s). The clinical features of osteomyelitis often do not differ from more superficial infections in the diabetic foot and that poses a great challenge for the diagnosis (Fig. 8.1.5).
• Systemic signs and symptoms, such as fever, a high white blood cell (WBC) count and elevated eryth-
rocyte sedimentation rate (ESR) may or may not be present. In fact more than half of all patients, including those with serious infections, lack a fever, a high WBC count and an elevated ESR [2, 26].
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...