A 25-year-old woman presents for evaluation of spontaneous discoloration of her toes. Aside from the appearance of her toes, she does not have additional complaints. The patient is a graduate student currently taking courses online. She has no history of systemic disease, and she denies illicit drug use. Other than a transient throat irritation, she denies recent fever, night sweats, cough, diarrhea, or loss of taste or smell. Examination reveals a reddish-purple discoloration of all toes.
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The patient is experiencing a vascular acrosyndrome associated with the 2019 novel coronavirus (COVID-19). This phenomenon, commonly referred to as COVID infection-induced chilblains or “COVID toes,” is believed to represent acute self-healing acro-ischemic lesions that are distinct from those related to acrocyanosis, perniosis, Henoch-Schönlein vasculitis, and protein C deficiency.1,2 These lesions may present as violaceous discolorations, papules, or plaques usually located on multiple toes.
The phenomenon appears to primarily affect younger individuals and may be the only identifiable sign of viral infection. One emerging theory hypothesizes that younger patients may exhibit an earlier type-I interferon response, effectively inhibiting viral replication while concurrently producing a chilblain lupus erythematosus-like response through microangiopathic changes.3 It is also postulated that COVID-19 may activate the coagulation cascade leading to systemic hypercoagulability and subsequent acral ischemia.4 The condition usually portends a benign clinical course and may possibly indicate a beneficial immune response to the virus.5
The incidence of COVID toes is unknown, although it is presumed that many asymptomatic individuals do not seek medical attention. Until recently, viral testing for COVID-19 was either not widely available or was reserved for individuals with more classic symptoms of infection.6 Given the pandemic, COVID-19 should be suspected in any individual presenting with acute onset of purplish discoloration of the feet and/or hands.7
Nelson Maniscalco, DPM, is a joint podiatry/dermatology fellow under the aegis of St. Luke’s Medical Center in Allentown, Pennsylvania, and the DermDox Center for Dermatology. Stephen Schleicher, MD, is director of the DermDox Center for Dermatology, associate professor of medicine at Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
1. Landa N, Mendieta-Eckert M, Fonda-Pascual P, Aguirre T. Chilblain‐like lesions on feet and hands during the COVID‐19 pandemic. Int J Dermatol. 2020;59(6):739-743.
2. Mazzotta F, Troccoli T. Acute acro-ischemia in the child at the time of COVID-19. International Federation of Podiatrists. https://img.beteve.cat/wp-content/uploads/2020/04/acroischemia-ENG.pdf. Published April 2020. Accessed June 3, 2020.
3. Kolivras A, Dehavay F, Delplace D, et al. Coronavirus (COVID-19) infection–induced chilblains: a case report with histopathologic findings. JAAD Case Rep. 2020;6(6):489-492.
4. Li T, Lu H, Zhang W. Clinical observation and management of COVID-19 patients. Emerg Microbes Infect. 2020;9(1):687-690.
5. Rabin RC. What is ʻCovid toeʼ? Maybe a strange sign of coronavirus infection. The New York Times. https://www.nytimes.com/2020/05/01/health/coronavirus-covid-toe.html?searchResultPosition=1. Published May 1, 2020. Accessed June 3, 2020.
6. Tosti G, Barisani A, Queirolo P, et al. Skin signs resembling vascular acrosyndromes during the COVID‐19 outbreak in Italy [published online May 2, 2020]. Clin Exp Dermatol. doi:10.1111/ced.14267
7. Basatneh R, Vlahovic TC. Addressing the question of dermatologic manifestations of SARS-CoV-2 infection in the lower extremities: a closer look at the available data and its implications [published online April 20, 2020]. J Am Podiatr Med Assoc. doi:10.7547/20-074