A diabetic foot exam is a systematic inspection designed to prevent serious complications that arise when high blood sugar levels damage nerves and blood vessels in the lower extremities. This damage, known as diabetic neuropathy and peripheral artery disease, leads to loss of sensation, poor circulation, and a reduced ability to heal. Since a person with diabetes may not feel a minor cut or blister, regular, comprehensive foot examinations are fundamental for early detection and risk stratification. Identifying these issues early prevents minor injuries from escalating into severe infections, which are a major cause of non-traumatic lower-limb amputations.
Essential Equipment and Patient Preparation
A thorough examination requires specific tools to accurately assess both neurological and vascular health. The 10-gram monofilament is used for sensation testing, applying a specific amount of force to the skin. A 128-Hz tuning fork is necessary to evaluate vibratory perception, which often detects nerve damage earlier than pressure sensation tests. The equipment also includes a reflex hammer to check the Achilles tendon reflex and a reliable light source for visual inspection.
Before the examination, the patient should be positioned comfortably, typically sitting or lying down with their feet fully accessible. Ensure the feet are clean and completely dry, and all socks and footwear have been removed. The clinician should inspect the patient’s shoes for signs of uneven wear, which may indicate a gait or structural issue. Reviewing the patient’s history for previous ulcers, amputations, or symptoms like tingling or leg pain is also necessary.
Step-by-Step Visual and Skin Assessment
The visual assessment starts with observing the foot’s shape and alignment. Look for structural deformities, such as bunions, hammer toes, or the “rocker-bottom” shape associated with Charcot neuroarthropathy. Inspecting the skin’s color and temperature provides clues about circulation; pallor or a marked temperature difference between the feet may suggest vascular issues.
The entire foot must be checked, including areas the patient cannot easily see, such as the sole (plantar surface) and the heel. Specific signs of concern include cuts, blisters, fissures, and excessive callus formation, which are pre-ulcerative lesions indicating high-pressure areas. The spaces between all the toes must be inspected for interdigital maceration or signs of fungal infection (athlete’s foot), as these can rapidly lead to skin breakdown. Nail abnormalities, such as ingrown or discolored nails, should also be documented, as they represent potential entry points for pathogens.
Testing for Neuropathy and Vascular Health
Testing for peripheral neuropathy begins with the 10-gram monofilament, which assesses protective sensation. The patient must close their eyes to prevent guessing when the filament is applied. The filament is pressed perpendicularly against standardized sites on the plantar surface until it bends or buckles, taking one to two seconds. Inability to feel this sensation at multiple sites indicates a significant loss of protective sensation, placing the patient at high risk for ulceration.
Neurological Assessment
Vibratory sensation is an important component of the neurological assessment, often performed using the 128-Hz tuning fork. The fork is struck and placed on a bony prominence, such as the dorsal aspect of the great toe, while the patient’s eyes are closed. This test can detect neuropathy in its earlier stages.
Vascular Assessment
The examination of the vascular system focuses on assessing blood flow by palpating the two main foot pulses: the dorsalis pedis pulse on the top of the foot and the posterior tibial pulse behind the inner ankle bone. The pulses should be characterized as either present or absent. Diminished or absent pulses suggest peripheral artery disease, which compromises the foot’s ability to heal. Capillary refill time is checked by pressing on a toe and observing how quickly color returns; a time greater than two seconds suggests poor circulation.
Interpreting Findings and Scheduling Follow-Up
The findings from the comprehensive exam are used to stratify the patient’s risk of developing a foot ulcer or requiring an amputation. The absence of protective sensation, confirmed by an abnormal monofilament test, signifies a high risk because the patient cannot feel injuries. Absent pulses suggest peripheral artery disease, which slows wound healing. Patients with no neuropathy or vascular issues are considered low-risk and require a comprehensive foot exam annually.
If a patient has neuropathy, peripheral artery disease, or a foot deformity, the recommended follow-up frequency increases to every three to six months. Immediate professional attention is necessary for non-healing wounds, new signs of infection like redness or warmth, or sudden loss of sensation. Patients must also be instructed on daily self-inspections, including checking between the toes, and wearing appropriate, protective footwear.