There has been a rise in the prevalence of perniolike lesions—erythematous to violaceous, edematous papules or nodules on the fingers or toes—during the coronavirus disease 2019 (COVID-19) pandemic. These lesions are referred to as “COVID toes.” Although several studies have suggested an association with these lesions and COVID-19, and coronavirus particles have been identified in endothelial cells of biopsies of pernio lesions, questions remain on the management, pathophysiology, and implications of these lesions.1 We provide a practical review for primary care clinicians and dermatologists on the current management, recommendations, and remaining questions, with particular attention to the distinctions for children vs adults presenting with pernio lesions.
Hypothetical Case of a Child Presenting With Acral Lesions
A 7-year-old boy presents with acute-onset, violaceous, mildly painful and pruritic macules on the distal toes that began 3 days earlier and have progressed to involve more toes and appear more purpuric. A review of symptoms reveals no fever, cough, fatigue, or viral symptoms. He has been staying at home for the last few weeks with his brother, mother, and father. His father is working in delivery services and is social distancing at work but not at home. His mother is concerned about the lesions, if they could be COVID toes, and if testing is needed for the patient or family. In your assessment and management of this patient, you consider the following questions.
What Is the Relationship Between These Clinical Findings and COVID-19?
Despite negative polymerase chain reaction (PCR) tests reported in cases of chilblains during the COVID-19 pandemic as well as the possibility that these lesions are an indirect result of environmental factors or behavioral changes during quarantine, the majority of studies favor an association between these chilblains lesions and COVID-19 infection.2,3 Most compellingly, COVID-19 viral particles have been identified by immunohistochemistry and electron microscopy in the endothelial cells of biopsies of these lesions.1 Additionally, there is evidence for possible associations of other viruses, including Epstein-Barr virus and parvovirus B19, with chilblains lesions.4,5 In sum, with the lack of any large prospective study, the weight of current evidence suggests that these perniolike skin lesions are not specific markers of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).6
Published studies differ in reporting the coincidence of perniolike lesions with typical COVID-19 symptoms, including fever, dyspnea, cough, fatigue, myalgia, headache, and anosmia, among others. Some studies have reported that up to 63% of patients with reported perniolike lesions developed typical COVID-19 symptoms, but other studies found that no patients with these lesions developed symptoms.6-11 Studies with younger cohorts tended to report lower prevalence of COVID-19 symptoms, and within cohorts, younger patients tended to have less severe symptoms. For example, 78.8% of patients in a cohort (n=58) with an average age of 14 years did not experience COVID-19–related symptoms.6 Based on these data, it has been hypothesized that patients with chilblainslike lesions may represent a subpopulation who will have a robust interferon response that is protective from more symptomatic and severe COVID-19.12-14
Current evidence suggests that these lesions are most likely to occur between 9 days and 2 months after the onset of COVID-19 symptoms.4,9,10 Most cases have been only mildly symptomatic, with an overall favorable prognosis of both lesions and any viral symptoms.8,10 The lesions typically resolve without treatment within a few days of initial onset.15,16
What Should Be the Workup and Management of These Lesions?
Given the currently available information and favorable prognosis, usually no further workup specific to the perniolike lesions is required in the case of an asymptomatic child presenting with acral lesions, and the majority of management will center around patient and parent/guardian education and reassurance. When asked by the patient’s parent, “What does it mean that my child has these lesions?”, clinicians can provide information on the possible association with COVID-19 and the excellent, self-resolving prognosis. An example of honest and reasonable phrasing with current understanding might be, “We are currently not certain if COVID-19 causes these lesions, although there are data to suggest that they are associated. There are a lot of data showing that children with these lesions either do not have any symptoms or have very mild symptoms that resolve without treatment.”
For management, important considerations include how painful the lesions are to the individual patient and how they affect quality of life. If less severe, clinicians can reassure patients and parents/guardians that the lesions will likely self-resolve without treatment. If worsening or symptomatic, clinicians can try typical treatments for chilblains, such as topical steroids, whole-body warming, and nifedipine.17-19 Obtaining a review of symptoms, including COVID-19 symptoms and general viral symptoms, is important given the rare cases of children with severe COVID-19.20,21
The question of COVID-19 testing as related to these lesions remains controversial, and currently there are still differing perspectives on the need for biopsy, PCR for COVID-19, or serologies for COVID-19 in patients presenting with these lesions. Some experts report that additional testing is not needed in the pediatric population because of the high frequency of negative testing reported to date.22,23 However, these children may be silent carriers, and until more is known about their potential to transmit the virus, testing may be considered if resources allow, particularly if the patient has a known exposure.10,12,16,24 The ultimate decision to pursue biopsy or serologic workup for COVID-19 remains up to clinical discretion with consideration of symptoms, severity, and immunocompromised household contacts. If lesions developed after infection, PCR likely will result negative, whereas serologic testing may reveal antibodies.