Wound healing is a complex process that uses specific cellular and biochemical actions to achieve wound closure. These processes (homeostasis, inflammation, proliferation, and maturation) occur over defined periods of time. They are often taken for granted as the wound innately granulates, contracts, and epithelializes under optimal conditions.
A wound begs the clinician’s attention when the healing processes stall and the wound does not progress to closure. This type of wound is deemed chronic; it is defined as an insult or injury that has failed to proceed through an orderly and timely process to produce anatomic and functional integrity or that has proceeded through the repair process without establishing a sustained anatomic and functional result.
Despite advances in wound care over the last few decades, many chronic wounds continue to be affected by local and systemic factors that impair the healing process. Local factors include bacterial load and infection, trauma, edema, pressure, and moisture. Systemic factors include age; chronic medical conditions, such as anemia, diabetes mellitus, and renal or hepatic dysfunction; stress; medications; tissue oxygenation; and nutrition status, such as vitamin, protein, or fluid deficiencies.
Clinicians commonly evaluate and manage the typical chronic wounds, such as pressure, vascular, and diabetic ulcers. However, many unusual wounds mimic these common chronic wounds. Because these unusual wounds are often incorrectly assessed, they can be easily misdiagnosed. Examples include pyoderma gangrenosum, calciphylaxis, toxic epidermal necrolysis, epidermolysis bullosa, polyarteritis nodosa, antiphospholipid antibody syndrome, cryoglobulinemia, cholesterol emboli, disseminated intravascular coagulation/purpura fulminans, bullous pemphigoid, and necrotizing fasciitis.
Misdiagnosis of a wound prolongs the patient’s suffering by delaying healing; increasing the emotional and financial toll on the patient, caregiver, and facility; and increasing medical liability. It also leads to improper medication delivery and topical treatments, which can further exacerbate the patient’s condition, mask symptoms, prolong accurate diagnosis, and increase morbidity or mortality.
This point is well illustrated in an article by Weenig et al1 on skin ulcers misdiagnosed as pyoderma gangrenosum. The authors reviewed 8 years’ worth of charts (240 from their facility and 157 from another one) in which wounds were diagnosed as pyoderma gangrenosum, but 10% of these were found to be misdiagnosed for a median of 10 months. The authors concluded that misdiagnosis exposes patients to substantial risks associated with the wound’s treatment, and a thorough workup is needed to rule out diagnoses that mimic pyoderma gangrenosum.
Tools to Avoid Misdiagnosis
Clinicians can reduce the chance of misdiagnosing a wound by using the following tools:
- the medical record, to accurately describe the wound’s characteristics at each patient visit;
- risk assessment tools, which ensure systematic evaluation of individual risk factors;
- nutrition risk assessment tools;
- manual screening tools, including the ankle-brachial index, lower leg and foot assessments, palpation of pulses and Doppler ultrasound, segmental blood pressures, Semmes-Weinstein monofilament testing, transcutaneous oxygen pressure, and vibration perception threshold assessment; and
- other diagnostic tests, such as laboratory values, bacterial swab cultures, tissue cultures, skin biopsies, and radiologic and vascular studies.
Let’s take a look at tracking laboratory values in more detail.
Tracking Laboratory Values
Laboratory values can be used to evaluate, manage, and monitor chronic underlying medical conditions and to determine the patient’s nutrition status. These values should be assessed on the first patient visit to establish a baseline for care. In addition, if healing has not occurred as expected, certain laboratory values can be monitored to ensure that local and systemic factors are not contributing to poor healing. Important parameters to evaluate include protein levels, complete blood count, erythrocyte sedimentation rate, liver function tests, glucose and iron levels, total lymphocyte count, blood urea nitrogen and creatinine levels, lipoprotein levels, vitamin and mineral levels, and urinalysis. Even if only one deterrent is present, healing cannot occur.
1. Weenig RH, Davis MD, Dahl PR, Su WP. Skin ulcers misdiagnosed as pyoderma gangrenosum. N Engl J Med 2002;347(18):1412–8.