Warfarin-induced skin necrosis

Thrombosis in the perforasome in idiopathic purpura fulminans with anti-protein S antibodies: Anatomical and clinical evidence to improve management

Idiopathic purpura fulminans (IPF) is a rare and severe form of purpura fulminans caused by acquired protein S deficiency. It can lead to severe thrombotic complications, such as large skin necrosis and amputation. The lesions almost exclusively affect the lower limbs, and their distribution is similar among patients with IPF, unlike classical purpura fulminans lesions. Our hypothesis is that vascular structures called perforasomes may be involved in IPF, possibly caused by protein S deficiency. We analyzed all case reports and case series published in the literature that provided sufficient data for an anatomical study of limb injuries. For precise localization of areas of necrosis, we examined each case using descriptions and images to determine whether they overlapped with vascular territories that include perforasomes. We analyzed twelve cases from the literature and identified six vascular territories: the anterolateral, anteromedial, and posterior territories of the upper leg, as well as the anterolateral, anteromedial, and posterolateral territories of the lower leg. For each territory, we described the most probable vascular damage and the corresponding perforasome. IPF is a complex multifactorial disease in which a direct involvement of perforating arteries may be suspected and taken into account in the surgical of lesions.

Adverse Drug Reactions of the Lower Extremities

Adverse drug reactions (ADRs) are a common cause of dermatologic consultation, involving 2 to 3 per 100 medical inpatients in the United States. Female patients are 1.3 to 1.5 times more likely to develop ADRs, except in children less than 3 years of age, among whom boys are more often affected. Certain drugs are more frequent causes, including aminopenicillins, trimethoprim-sulfamethoxazole, and nonsteroidal antiinflammatory drugs. Chemotherapeutic agents commonly cause adverse reactions to the skin and nails, with certain agents causing particular patterns of reactions. ADRs can involve any area of the skin; the appendages, including hair and nails; as well as mucosa.

[Skin necrosis with vitamin K antagonists: An imbalance between coagulant and anticoagulant factors]

INTRODUCTION

Skin necrosis with vitamin k antagonists are rare. They affect more frequently middle-aged and obese women, often within 10 days after initiating of treatment. They occur most often in a context of thrombophilia.

CASE REPORT

An 18-year-old obese woman was treated with heparin and fluindione for a lower limb deep venous thrombosis. On day 5, the patient presented fever and skin necrosis, which extended rapidly. We identified an activated protein C resistance and a major inflammatory syndrome related to Mycoplasma pneumoniae infection. The outcome was favorable after discontinuation of the fluindione, introduction of heparin and vitamin K, despite amputation of a toe.

CONCLUSION

Skin necrosis is due to a transient hypercoagulable state during the initiation of vitamin K antagonist treatment due to an imbalance between pro- and anticoagulant factors. In our case, it was caused by an activated protein C resistance and an inflammatory syndrome.

Warfarin-induced skin necrosis

BACKGROUND

Warfarin is a frequently used oral anticoagulant in the treatment and prevention of various medical conditions. One uncommon adverse effect that can occur following the initiation of therapy is warfarin-induced skin necrosis. Because it is a rare effect with an undetermined pathophysiology of disease, the treatment is not well established.

CASE

A 52-year-old female was prescribed warfarin and enoxaparin for a newly diagnosed deep vein thrombosis (DVT) in the left lower extremity. On day 4 of therapy, the patient had a supra-therapeutic international normalized ratio (INR), prompting the discontinuation of enoxaparin and a decrease in the warfarin dose. The patient returned to the emergency department on day 7 of treatment with a purple, cold, and extremely painful right foot with punctate areas of necrosis and petechiae proximal to the discoloration. The patient's INR was found to be 10.64. Following the diagnosis of warfarin-induced skin necrosis, the patient was administered vitamin K intravenously and fresh frozen plasma (FFP) to reverse the effects of warfarin and promote protein C and S synthesis. Once the patient's INR was no longer supratherapeutic, subcutaneous enoxaparin was re-started as treatment for the known recent DVT. The patient's necrotic foot began to improve and she was discharged home with an anticipated full recovery.

CONCLUSIONS

Based on the proposed pathophysiology of disease, adequate bridge therapy may decrease the likelihood of developing this life-threatening condition. Early recognition and treatment with intravenous vitamin K, FFP or 4-factor prothrombin complex concentrate, and continued wound care are essential to prevent further complications.

Warfarin-induced skin necrosis

BACKGROUND

Warfarin is a frequently used oral anticoagulant in the treatment and prevention of various medical conditions. One uncommon adverse effect that can occur following the initiation of therapy is warfarin-induced skin necrosis. Because it is a rare effect with an undetermined pathophysiology of disease, the treatment is not well established.

CASE

A 52-year-old female was prescribed warfarin and enoxaparin for a newly diagnosed deep vein thrombosis (DVT) in the left lower extremity. On day 4 of therapy, the patient had a supra-therapeutic international normalized ratio (INR), prompting the discontinuation of enoxaparin and a decrease in the warfarin dose. The patient returned to the emergency department on day 7 of treatment with a purple, cold, and extremely painful right foot with punctate areas of necrosis and petechiae proximal to the discoloration. The patient's INR was found to be 10.64. Following the diagnosis of warfarin-induced skin necrosis, the patient was administered vitamin K intravenously and fresh frozen plasma (FFP) to reverse the effects of warfarin and promote protein C and S synthesis. Once the patient's INR was no longer supratherapeutic, subcutaneous enoxaparin was re-started as treatment for the known recent DVT. The patient's necrotic foot began to improve and she was discharged home with an anticipated full recovery.

CONCLUSIONS

Based on the proposed pathophysiology of disease, adequate bridge therapy may decrease the likelihood of developing this life-threatening condition. Early recognition and treatment with intravenous vitamin K, FFP or 4-factor prothrombin complex concentrate, and continued wound care are essential to prevent further complications.

Dermatological Conditions Mimicking Trauma

A number of dermatological findings may mimic inflicted injury in forensic investigations and lead to false conclusions about the circumstances, manner, and mechanism of death. At times, organic dermatological phenomena involving the skin, hair, and nails are initially misidentified as trauma, sexual abuse, or burns. History, autopsy, and histopathology aid in correctly diagnosing these dermatological findings. Some of the resulting diagnoses include pruritic, ulcerating, and infectious skin diseases, skin disease localized to the anogenital area, malignancy, medication-induced dermatoses, alopecia, and age-related skin changes. We report several cases where police and/or the coroner initially attributed a finding to trauma, but it was subsequently determined that the finding represented a dermatological disease by the forensic pathologist upon autopsy. In addition, for completeness, we include examples of other dermatological conditions that may mimic trauma. Forensic investigators should maintain a broad differential for abnormal skin, hair, and nail findings when there is an incomplete or incongruent history surrounding a victim's death.