Peer Reviewed

Photo Quiz

Identification of a Chronic Lower Extremity Wound in a Patient With a Mechanical Valve

Rachel Blansfield, BS,
Nicholas Jennelly, MD,
Thomas N. Helm, MD

  • Correct answer: D. Calciphylaxis

    The presence of fibrointimal hyperplasia associated with small and medium vessel calcification and thrombosis supports a diagnosis of calciphylaxis. Given the temporal relationship to warfarin initiation and the absence of end-stage renal disease at the time of warfarin initiation, the patient was diagnosed with warfarin-induced calciphylaxis.

    Outcome and follow-up. While hospitalized, she received a sodium thiosulfate (STS) infusion but developed severe anion gap metabolic acidosis (pH 7.1, bicarbonate 9 mmol/L, anion gap 22). STS was discontinued, and intravenous bicarbonate was administered, resulting in a resolution of her anion gap and an improvement in her metabolic acidosis (pH 7.3, bicarbonate 19.6 mmol/L, anion gap 13).  She was given a 10-day course of ciprofloxacin and doxycycline for secondary infection.  After multidisciplinary discussion with cardiology, nephrology, and dermatology, her anticoagulation was transitioned from warfarin to renally dosed enoxaparin upon discharge from the hospital. She has not experienced any thrombotic complications on enoxaparin. Despite discontinuing warfarin, her ulcers persisted and she underwent above-the-knee amputation of her right lower extremity 6 months after discharge.

    Discussion. Calciphylaxis is a vascular calcification disorder characterized by ischemic, painful skin ulcers with high morbidity and a 1-year mortality rate of 45% to 80%.1,2 While most cases occur in end-stage renal disease, warfarin-associated calciphylaxis may also occur in patients without end-stage renal disease.3 Unlike calciphylaxis associated with advanced renal disease, lesions in warfarin-associated nonuremic calciphylaxis often occur below-the-knee and may occur without the marked mineral abnormalities classically seen in end-stage renal disease.4 Pyoderma gangrenosum is associated with a dense neutrophilic infiltrate in the dermis. Vasculitis is associated with inflammation and fibrin in vessel walls without calcification. Atherosclerosis is associated with lipid-laden foam cells and development of a fibrous cap comprised of collagen and smooth muscle cells.

    Avoiding precipitating causes is key to management of calciphylaxis. STS is often used to increase calcium solubility and promote healing. Although many patients improve on this therapy, adverse effects such as nausea, vomiting, and metabolic acidosis may occur.2 Severe acidosis, usually reported in those with renal failure, has been demonstrated in several case reports and is associated with high mortality.5-9

    The significant morbidity associated with warfarin-induced calciphylaxis presents a difficult clinical challenge in patients with mechanical heart valves as warfarin remains the only FDA-approved anticoagulant.10 Alternative agents such as enoxaparin have been used off-label with success in case reports, however, no large trials support the use of alternative anticoagulants.11 This case highlights the delicate balance between anticoagulation and wound management in warfarin-induced calciphylaxis.

    AUTHORS
    Rachel Blansfield, BS,1,2 Nicholas Jennelly, MD,2 Thomas N. Helm, MD2

    AFFILIATIONS:
    1Penn State College of Medicine, Hershey, PA
    2Penn State Health Milton S. Hershey Medical Center, Hershey, PA

    CITATION:
    Blansfield R, Jennelly N, Helm TN. Identification of a chronic lower extremity wound in a patient with a mechanical valve. Consultant. Published online April 14, 2026. doi:10.25270/con.2026.04.000002

    Received: November 20, 2025. Accepted: January 19, 2026.

    DISCLOSURES:
    The authors report no relevant financial relationships.

    ACKNOWLEDGEMENTS:
    None.

    CORRESPONDENCE:
    Rachel Blansfield, BS, Penn State College of Medicine, 700 HMC Cres Rd., Hershey, PA, 17033 (email: rblansfield@pennstatehealth.psu.edu)

    References

    1. Colboc H, Moguelet P, Bazin D, et al; Groupe Angio-Dermatologie of the French Society of Dermatology. Localization, morphologic features, and chemical composition of calciphylaxis-related skin deposits in patients with calcific uremic arteriolopathy. JAMA Dermatol. 2019;155(7):789–796. doi:10.1001/jamadermatol.2019.0381
    2. Nigwekar SU, Kroshinsky D, Nazarian RM, et al. Calciphylaxis: risk factors, diagnosis, and treatment. Am J Kidney Dis. 2015;66(1):133-146. doi:10.1053/j.ajkd.2015.01.034
    3. Danziger J. Vitamin K–dependent proteins, warfarin, and vascular calcification. Clin J Am Soc Nephrol. 2008;3(5):1504-1510. doi:10.2215/CJN.00780208
    4. Yu WY, Bhutani T, Kornik R, et al. Warfarin-Associated Nonuremic Calciphylaxis. JAMA Dermatol. 2017;153(3):309-314. doi:10.1001/jamadermatol.2016.4821
    5. Selk N, Rodby RA. Unexpectedly severe metabolic acidosis associated with sodium thiosulfate therapy in a patient with calcific uremic arteriolopathy. Semin Dial. 2011;24(1):85-88. doi:10.1111/j.1525-139X.2011.00848.x
    6. Mao M, Lee S, Kashani K, Albright R, Qian Q. Severe anion gap acidosis associated with intravenous sodium thiosulfate administration. J Med Toxicol. 2013;9(3):274-277. doi:10.1007/s13181-013-0305-z
    7. Rein JL, Miyata KN, Dadzie KA, Gruber SJ, Sulica R, Winchester JF. Successfully treated calcific uremic arteriolopathy: two cases of a high anion gap metabolic acidosis with intravenous sodium thiosulfate. Case Rep Nephrol. 2014;2014:765134. doi:10.1155/2014/765134
    8. Homan MP, Tadros MG, Guzzo JC. Severe metabolic acidosis due to sodium thiosulfate in peritoneal dialysis. J Am Soc Nephrol. 2022;33(11S):922. doi:10.1681/ASN.20223311S1922b
    9. Abdalla M, Faris ME, Saad E, Meng Q, Friedman H, Soifer N. Profound metabolic acidosis in association with sodium thiosulfate therapy in a patient with calcific uremic arteriolopathy: a case report and literature review. CEN Case Rep. 2024;13(1):59-65. doi:10.1007/s13730-023-00801-x
    10. Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2021;143(5):e35-e71. doi:10.1161/CIR.0000000000000932
    11. Wang X, Mathew C, Korapati S, Bathini VG. Successful long-term anticoagulation with enoxaparin in a patient with a mechanical heart valve. Pharmacotherapy. 2020;40(2):174-177. doi:10.1002/phar.2361

    ©2026 HMP Global. All Rights Reserved. Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of Consultant360 or HMP Global, their employees, and affiliates.