DISCUSSION

Chilblain inflammation is an abnormal reaction to cold and damp environments, characterized by painful cutaneous lesions involving the distal extremities. Rarely, chilblains are associated with systemic disease like systemic lupus erythematosus. This patient presented to the ED with no underlying risk factors for lesion development. It is particularly unusual for chilblain lesions to appear in warmer spring temperatures, especially in the context of home confinement.^{Reference Lopez-Robles, de la Hera and Pardo2} Investigations of this patient also did not reveal any systemic disease. In this context, and based on observations reported elsewhere, it is suspected that these lesions were induced by COVID-19.

In Europe, case reports and case series have described COVID-19-associated skin lesions, highlighting an outburst of chilblain-like lesions contemporaneously related to the COVID-19 epidemic.^{Reference Lopez-Robles, de la Hera and Pardo2,Reference Landa, Mendieta-Eckert and Fonda-Pascual3} Chilblain-like lesions were first reported by Mazzotta et al.^{Reference Mazzotta and Troccoli6} in a case study of a child with suspected COVID-19. Since then, nationwide studies have explored the association between COVID-19 and cutaneous symptoms. In Spain, a “pseudo-chilblain” clinical pattern was identified in a prospective study of 375 patients presenting with cutaneous findings and confirmed COVID-19.^{Reference Galvan Casas, Catala and Carretero Hernandez4} Similar studies have since been published in France and Italy supporting these clinical findings.^{Reference De Masson, Bouaziz and Sulimovic1,Reference Piccolo, Neri and Filippeschi5}

Our patient's clinical presentation is nearly identical to that reported in the medical literature. Chilblain-like lesions associated with COVID-19 tend to occur in pediatric populations who are often otherwise asymptomatic or young adults, like our patient, who tend to present with flu-like symptoms 3–4 weeks before lesion onset.^{Reference Landa, Mendieta-Eckert and Fonda-Pascual3} Like our patient, lesions are reported to appear as violaceous macules, which can sometimes be painful or itchy and typically target the feet, particularly the dorsal surface of the toes, though there have been some reports of digit involvement as well.^{Reference Galvan Casas, Catala and Carretero Hernandez4,Reference Piccolo, Neri and Filippeschi5}

Unfortunately, COVID-19 testing was not completed while this patient had illness symptoms. Though her symptoms might be consistent with other viral infections, given her known COVID-19 exposure and the recent association between similar lesions and confirmed cases, it is strongly suspected that this patient had been infected with COVID-19.

Interestingly, our patient tested negative for COVID-19 virology in the ED. This is consistent with published literature, which suggests that some patients have no demonstrable evidence of active infection when presenting with such lesions.^{Reference Lopez-Robles, de la Hera and Pardo2,Reference Galvan Casas, Catala and Carretero Hernandez4} It has been hypothesized that these cutaneous findings could be a delayed manifestation of COVID-19.^{Reference Galvan Casas, Catala and Carretero Hernandez4} In European countries such as France, the outbreak of these lesions was only reported during the third week of containment, providing support to this hypothesis.^{Reference Landa, Mendieta-Eckert and Fonda-Pascual3} To date, the exact mechanism of these lesions remains unknown; however, several hypotheses suggest that vasculopathy is involved in the pathogenesis.^{Reference De Masson, Bouaziz and Sulimovic1}

As the COVID-19 pandemic continues to evolve, there will likely be an increase in chilblain-like presentations to the ED. To date, these lesions have been reported to be self-limiting and resolve favourably.^{Reference Landa, Mendieta-Eckert and Fonda-Pascual3} Unless there is evidence of further systemic vasculopathy, treatment in the ED should be supportive, aimed at symptom management and prevention of complications related to skin breakdown. It is uncertain whether medications used for chilblains to increase digital blood flow and decrease pain, such as calcium channel blockers, would be useful for this COVID-19 manifestation.