What are the red flags in the history and physical examination of a patient with Diabetes Mellitus (DM) presenting with foot pain following recent foot trauma?

From the Guidelines

Red flags in a diabetic patient with recent foot trauma and pain require immediate attention to prevent serious complications, and key warning signs include signs of infection, systemic infection, vascular compromise, and tissue death, as identified in the 2023 standards of care in diabetes 1. The most critical red flags to look out for in these patients include:

• Signs of infection such as redness, warmth, swelling, purulent drainage, or foul odor
• Fever, chills, or elevated inflammatory markers suggesting systemic infection
• Open wounds, especially those with exposed bone or tendon, indicating high risk for osteomyelitis
• Crepitus (crackling sensation under the skin) signaling gas-forming organisms requiring urgent intervention
• Severe pain disproportionate to the injury, which could indicate deep space infection or Charcot neuroarthropathy
• Diminished or absent pulses, delayed capillary refill, or cool extremities suggesting vascular compromise
• Areas of black or necrotic tissue indicating tissue death requiring debridement
• Rapid onset of symptoms, particularly after seemingly minor trauma, warrants concern
• A history of poor glycemic control increases infection risk, while previous foot ulcers or amputations indicate higher vulnerability These patients should be evaluated promptly, often with imaging studies like X-rays to assess for osteomyelitis or fractures, and may require urgent surgical consultation, as diabetic foot infections can progress rapidly to limb-threatening conditions due to the combination of neuropathy, vascular disease, and immune dysfunction common in diabetes, as noted in the 2012 infectious diseases society of america clinical practice guideline for the diagnosis and treatment of diabetic foot infections 1. Additionally, a comprehensive foot evaluation should be performed at least annually to identify risk factors for ulcers and amputations, including inspection of the skin, assessment of foot deformities, neurological assessment, and vascular assessment, as recommended in the 2023 standards of care in diabetes 1 and the 2018 standards of medical care in diabetes 1. The presence of systemic signs or symptoms generally signifies severe infection with extensive tissue involvement or more virulent pathogens, and elevated inflammatory markers have been shown to predict worse clinical outcomes of treatment, as discussed in the 2012 infectious diseases society of america clinical practice guideline for the diagnosis and treatment of diabetic foot infections 1. A multidisciplinary approach is recommended for individuals with foot ulcers and high-risk feet, and referral to foot care specialists for ongoing preventive care and lifelong surveillance is advised for those who smoke and have a history of prior lower-extremity complications, loss of protective sensation, structural abnormalities, or peripheral arterial disease, as stated in the 2023 standards of care in diabetes 1. Overall, prompt evaluation and management of diabetic patients with recent foot trauma and pain are crucial to prevent serious complications and improve outcomes, as emphasized in the 2012 infectious diseases society of america clinical practice guideline for the diagnosis and treatment of diabetic foot infections 1 and the 2023 standards of care in diabetes 1.

From the Research

Red Flags in History

• Recent foot trauma in a diabetic patient presenting with foot pain may indicate a high risk of developing severe diabetic foot disease, including infection and ischemia 2, 3
• A history of poorly controlled diabetes, previous foot ulcers, or amputations may also increase the risk of complications 4, 5
• The presence of systemic symptoms such as fever, chills, or malaise may indicate a severe infection requiring prompt medical attention 2, 6

Red Flags in Exam

• Signs of severe infection, such as increased redness, swelling, warmth, or purulent discharge, may indicate a diabetic foot attack requiring immediate surgical intervention and broad-spectrum antibiotic therapy 2, 6
• The presence of a foul odor or crepitus may indicate gas gangrene, a life-threatening condition requiring prompt treatment 3, 6
• Decreased peripheral pulses, cool skin, or decreased capillary refill may indicate ischemia, which can lead to tissue necrosis and amputation if left untreated 4, 5
• Neurological deficits, such as numbness, tingling, or loss of sensation, may indicate peripheral neuropathy, which can increase the risk of foot ulcers and other complications 3, 5