Woman With Leg Rash
Article Outline
[Ann Emerg Med. 2010;56:71.]
A 47-year-old woman presented to the emergency department (ED) with a rash developing on her thighs, knees, and left buttock during the previous day, with significant pain throughout the affected areas (Figure 1, Figure 2). She presented 1 day after discharge from the medical intensive care unit for hypertensive emergency, where she was diagnosed with bilateral lower-extremity deep venous thrombosis; she began receiving intravenous heparin and received an initial dose of warfarin 10 mg. Two days later, warfarin was decreased to 7.5 mg daily; she was discharged 4 days after initiation of therapy, with an international normalized ratio of 4.6. On presentation to the ED, international normalized ratio was 6.9.
Figure 1.
Painful skin rash and discoloration appearing over lower extremity over previous day.
Figure 2.
Extension of rash involving both lower extremities.
Used with permission of Adam Brenner, MD, University of Maryland Medical Center, Department of Emergency Medicine, Baltimore, MD.
Diagnosis
Warfarin-induced skin necrosis
Warfarin-induced skin necrosis occurs in 0.01% to 0.1% of patients who begin receiving warfarin therapy. In 93% of cases, symptoms begin 3 to 6 days after initiation of therapy, but cases have been reported as late as 18 months.1 Diagnosis is made clinically, with rash, usually appearing over fatty areas, most commonly over the breasts, followed by the thighs/buttocks (Figure 1, Figure 2).2 It is more common in middle-aged, perimenopausal women with venous thromboembolism.2 Seventy-five percent of patients with warfarin-induced skin necrosis who begin receiving treatment for deep venous thrombosis or pulmonary embolism may have baseline-depleted protein C and S activity caused by consumption by the thrombotic process.1 Pathophysiology may also involve large loading doses of warfarin, thrombosis of superficial dermal capillaries, and inherited protein C and S deficiencies.2 Treatment entails discontinuation of warfarin and replenishing vitamin K–dependent factors, accompanied with debridement, grafting, or amputation as needed for skin necrosis. Heparin should be used for long-term treatment of thromboembolic disease.1, 2
References
For the diagnosis and teaching points, see page 81.
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PII: S0196-0644(09)01448-6
doi:10.1016/j.annemergmed.2009.08.021
© 2010 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
