Zellers, Norman D. MSPAS, PA-C
Norman D. Zellers represents the Air Force in the Army-Baylor University Doctorate of Science in Physician Assistant Study in Emergency Medicine residency based at the San Antonio Military Medical Center in Tex. The author has indicated no relationships to disclose relating to the content of this article.
Adrian Banning, MMS, PA-C, department editor
A 41-year-old man presented to a local express medical clinic with a fever of 101.8° F (38.8° C) and a chief complaint of left lower extremity pain and erythema. He reported associated knee pain for the previous 3 days. He was given acetaminophen for his fever before being transferred to the ED for further evaluation and care of “possible cellulitis with knee joint infection.”
History Upon further questioning at the ED the patient stated that he had 3 days of bilateral lower extremity pain without edema to the thigh or calves, along with noted erythema to the upper left thigh (Figure 1). His stated pain was 9 on a 0-to-10 pain intensity rating scale, and the pain was not relieved by acetaminophen. As for an inciting event for infection, he reported that a rooster on his farm “had issues with me every time I'd go to feed the hens.” Reportedly, the rooster would attack the man, using his spurs to scratch at the man's knees, but about 3 days ago, the rooster scratched the man's left thigh. He was uncertain if skin integrity was disrupted. The patient denied numbness or weakness of his lower extremities. He reported minor cold symptoms but denied history of recent travel, trauma, surgery, hospitalization, chest pain, shortness of breath, or hemoptysis. He did report recent unintentional weight loss of about 30 pounds in the last 3 months, and a few episodes of nonbloody diarrhea over the past couple of days, which appeared to be resolving. His past medical history was unremarkable for venous thrombosis. His family history was positive for breast cancer. He had a one-pack-per-day smoking history for 20 years but quit 12 days before arriving at the ED. He reported a strong history of alcohol use and occasional nasal cocaine use in the past but had quit both habits more than 6 months previously. He had no allergies and was taking no medication.
Physical examination Vital signs in the ED were BP, 118/67 mm Hg; heart rate, 128; respirations, 20; temperature, 100.8° F (38.2° C); and SpO2, 94% on room air. He was alert and oriented and was in no apparent distress. The examination was completely unremarkable except for the left lower extremity evaluation. A pinpoint mark was noted on the inner aspect of the left thigh; this mark had no scabbing but visible surrounding erythema. His left inner thigh had palpable warmth and moderate tenderness. No fluctuance or masses were noted and he had a negative Homans sign. His left knee was tender but without warmth, erythema, or loss of motion. His neurovascular status was intact.
WHAT IS YOUR DIAGNOSIS?
* Deep vein thrombosis (DVT)
* Compartment syndrome
* Infectious psittacosis
The patient had a DVT. Many patients presenting with a DVT have more than one acquired risk factor for thrombosis. The six most prevalent preexisting medical characteristics of patients in one study were (in descending order of frequency): more than 48 hours of immobility in the preceding month, hospital admission in the last 3 months, surgery in the last 3 months, malignancy in the last 3 months, infection in the last 3 months, and current hospitalization.1
Thrombotic episodes may also precede the diagnosis of malignancy by months or years.2 Our patient had an impressive smoking history, with unexplained weight loss along with a family history of breast cancer. During his hospital stay he received a CT scan of his chest, abdomen, and pelvis, which did not reveal an occult tumor.
Compartment syndrome usually is a sequela of trauma and typically presents with pain out of proportion to the examination with passive range-of-motion pain. The case patient did not have this type of pain. Concomitant cellulitis was a possibility, but abscess was later ruled out by a comprehensive ultrasound. Humans may acquire psittacosis from inhaling dust from dried bird feces, feather dust, or aerosolized avian respiratory secretions, not from bird scratches.
The patient was initially given fluids and analgesics while results from the workup were pending. A chest radiograph was ordered and revealed no cardiopulmonary abnormalities. A complete blood cell (CBC) count, comprehensive metabolic panel, and blood cultures were ordered. A bedside ultrasound of the lower extremity was performed to check for underlying abscess pockets and DVT. No subcutaneous fluid pockets were noted, but the left common femoral vein was not compressible, indicating thrombosis. A comprehensive ultrasound confirmed that the patient had occlusive thrombosis from his proximal left femoral to popliteal vein.
The CBC revealed leukocytosis (white blood cell count of 16,800 cells/mm3), suggesting a concomitant infective process versus an acute phase reaction. The blood cultures later came back negative. A coagulation panel was drawn for baseline to begin anticoagulation therapy, and surprisingly showed an international normalized ratio (INR) of 2.2. The patient had not been on warfarin and had no known bleeding disorders in his past or family history. Vascular surgery was consulted for possible thrombectomy, lysis, or inferior vena cava filter placement, but they decided to withhold surgical interventions due to the possibility of infection. IV antibiotics were converted to oral preparations for home therapy. Because even patients with an elevated INR can be hypercoagulable, the patient was maintained on therapeutic low-molecular-weight heparin for 3 to 6 months (length to be determined as an outpatient) and not bridged to warfarin because his INR would be difficult to follow due to the elevated level on presentation.3
Hematology was consulted regarding the elevated INR and on discharge was considering possible chronic liver disease, inadequate vitamin K in the patient's diet, or possible inherited hypercoagulable disease such as factor V Leiden mutation and prothrombin gene mutation. These two mutations account for 50% to 60% of cases of hypercoagulability.4
Cases like this remind clinicians to keep suspicions high and differentials broad. Although the initial diagnosis may be correct, other underlying life-threatening causes must be considered. Had the clinicians not suspected DVT, this patient may have been treated for a superficial cellulitis and sent home on oral antibiotics, only to present later with a pulmonary embolism or worse.
1. Spencer FA, Emery C, Lessard D, et al. The Worcester Venous Thromboembolism study: a population-based study of the clinical epidemiology of venous thromboembolism. J Gen Intern Med
2. Goldenberg N, Kahn SR, Solymoss S. Markers of coagulation and angiogenesis in cancer-associated venous thromboembolism. J Clin Oncol
3. Dabbagh O, Oza A, Prakash S, et al. Coagulopathy does not protect against venous thromboembolism in hospitalized patients with chronic liver disease. Chest
4. Crowther MA, Kelton JG. Congenital thrombophilic states associated with venous thrombosis: a qualitative overview and proposed classification system. Ann Intern Med
© 2014 American Academy of Physician Assistants.