Dermoscopy of chilblain-like lesions during the COVID-19 outbreak: A multicenter study on 10 patients
Authors: Vincenzo Piccolo, Andrea Bassi, Giuseppe Argenziano, Carlo Mazzatenta, Alba Guglielmo, Annalisa Patrizi, Iria Neri
Journal: Journal of the American Academy of Dermatology (2020)

To the Editor: We recently reported 63 patients who developed chilblain-like lesions (CBL) during the COVID-19 pandemic, but the association with severe acute respiratory syndrome coronavirus 2 has not been proven.1Piccolo V. Neri I. Filippeschi C. et al.Chilblain-like lesions during COVID-19 epidemic: a preliminary study on 63 patients.J Eur Acad Dermatol Venereol. 2020; 34: e291-e293Crossref PubMed Scopus (195) Google Scholar Because most patients' information was not previously obtained by in-person visits by the investigators, dermoscopy was not available. Ten patients with CBL were recruited from April 1 to 15, 2020 (Table I). There were 7 male and 3 female patients, with a median age of 13 years (range, 11-20 y). The feet were mostly affected (8/10 patients). The erythematous-edematous type was seen in 8 of 10 patients, and the blistering type was observed in 2 of 10 patients. The median time to diagnosis was 13 days (range, 6-34 d). Patients were otherwise healthy, and COVID-19 status, when investigated through swab (1/10) or serology (2/10), was negative.Table IPatients' characteristicsPatientSexAge, yLocationTime to diagnosis, dClinical typeDermoscopyBackgroundVesselsOther findings1M20Feet14Erythematous-edematousErythematousDotted—2M11Feet33Erythematous-edematousErythematousLinear—3M13Feet34BlisteringCoppery redHemorrhagic dots, linear—4F12Feet10Erythematous-edematousCoppery redHemorrhagic dots—5M14Feet10Erythematous-edematousCoppery redHemorrhagic dotsCrustsPurple unstructured areasBullae6M13Feet12BlisteringCoppery redHemorrhagic dotsGlomerular VesselsCrustsPurple unstructured areas7F11Hands/feet10Erythematous-edematousCoppery redIrregular linear vesselsCuticular vesselsVessels with branchesMultiple short vessels arranged perpendicularlyPurple unstructured areas8F13Hands15Erythematous-edematousErythematousHemorrhagic dotsIrregular dotsCuticular vessels—9M12Feet6Erythematous-edematousCoppery redHemorrhagic dotsDotted, irregular linear vesselsRound brown unstructured area with within halo10M13Feet17Erythematous-edematousErythematousDotted—F, Female; M, male. Open table in a new tab F, Female; M, male. Dermoscopy evaluated background color, vessels, and additional features. Background color was coppery red in 6 of 10 and red in 4 of 10 patients. Erythema was blanching in early cases, and it did not disappear in long-standing red-purple lesions. In plantar lesions, erythema mostly involved ridges. Vessels were seen in all patients. Hemorrhagic dots were commonly detectable (6/10); nonblanching blurred dotted, linear, glomerular, and irregular vessels were occasionally found. Additional features, including crusts and whitish areas, were seen in the blistering type (Figs 1 and 2). Because there was an outbreak of CBL, it was quite logical to think about a causal relationship between COVID-19 and CBL, although poor data about patients' COVID status did not allow us to confirm this supposition.1Piccolo V. Neri I. Filippeschi C. et al.Chilblain-like lesions during COVID-19 epidemic: a preliminary study on 63 patients.J Eur Acad Dermatol Venereol. 2020; 34: e291-e293Crossref PubMed Scopus (195) Google Scholar,2Piccolo V. Neri I. Manunza F. Mazzatenta C. Bassi A. Chilblain-like lesions during the COVID-19 pandemic: should we really worry?.Int J Dermatol. 2020; 59: 1026-1027Crossref PubMed Scopus (20) Google Scholar Most patients were adolescents, and only a minority presented mild systemic symptoms preceding cutaneous signs. A possible mechanism could be a delayed immune reaction to the viral infection leading to microvascular damage and secondary development of cutaneous lesions. Dermoscopy could be a support in discovering the morphologic features of CBL and the potential pathogenesis hiding behind this mysterious sign. In most patients, a coppery red background was present at dermoscopy, probably indicating the presence of inflammatory cells and hemosiderin in the dermis. The presence of vascular damage was also indicated by hemorrhagic dots and nonblanching vessels. The presence of some additional features in the blistering type confirms that there was skin detachment in those patients. These dermoscopic findings could be partially justified by the histologic features recently described,3Colmenero I. Santonja C. Alonso-Riaño M. et al.SARS-CoV-2 endothelial infection causes COVID-19 chilblains: histopathological, immunohistochemical and ultrastructural study of 7 paediatric cases. Br J Dermatol.https://doi.org/10.1111/bjd.19327Google Scholar with dermal and perivascular lymphocyte infiltrate associated with keratinocyte necrosis. Dermoscopic findings of CBL are not novel, because they overlap with those of pigmented purpuric dermatoses (PPD)4Piccolo V. Russo T. Moscarella E. Brancaccio G. Alfano R. Argenziano G. Dermatoscopy of vascular lesions.Dermatol Clin. 2018; 36: 389-395Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar and chilblains. The combination of coppery-red background with hemorrhagic dots is typical of the PPD, whose association with viral infections has been sometimes documented. On the other hand, the similarity of CBL to chilblains is not only clinical but also dermoscopic, so we maintain that the denomination of CBL for this cutaneous sign could be the most appropriate and that the term acro-ischemia should be avoided.5Piccolo V. Bassi A. Acral findings during the COVID-19 outbreak: chilblain-like lesions should be preferred to acro-ischemic lesions.J Am Acad Dermatol. 2020; 83: e231https://doi.org/10.1016/j.jaad.2020.05.077Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar The dermoscopic analogy with PPD could suggest a common histopathology, with a perivascular lymphocyte infiltration and augmented erythrocyte extravasation, although different reasons could lie at the bases of the 2 different conditions. Our preliminary dermoscopic observations suggest a possible pathogenic explanation for this poorly understood condition.