A case of onychomadesis associated with chilblain‐like lesions after COVID‐19 infection

To the Editor,

Chilblain‐like lesions (CLLs) were widely described in children and adolescents during the coronavirus disease 2019 (COVID‐19) pandemic. Increasing evidence suggests the COVID‐19 correlation and several different associated manifestations are reported. Hereby, we present a 11‐year‐old girl who was referred to the Paediatric Dermatology Unit of Fondazione IRCCS Ca′ Granda in Milan on 27 January 2022 with a 7‐day history of nail shedding involving upper extremities. The patient started noting the nail changes 3 days after resolution of painful, erythematous plaques above both hands and was diagnosed as CLLs. Her medical history revealed COVID‐19 infection confirmed by a nasopharyngeal swab performed on 2021 December. She referred mild symptoms including diarrhoea, abdominal pain and fever (temperature 38°C) that did not require any treatment. Skin examination demonstrated onychomadesis of II, III, IV right hand's fingernails and II left hand's fingernail. Moreover, a residual dusky erythematous macule was noticed on the lateral margin of II right hand's finger. Laboratory testing, including complete blood count and C‐reactive protein, was within normal range. Cytomegalovirus, Epstein–Barr virus, Parvovirus B19, Coxsackievirus serology and Mycoplasma pneumoniae did not show any recent infection. To our knowledge, this is the first report of onychomadesis associated with chilblain‐like lesions after Sars‐CoV‐2 infection. Onychomadesis is the result of nail matrix temporary arrest secondary to numerous causes, including infections and inflammatory dermatosis. ¹ However, in case of viral infection (e.g. Coxsackievirus), it is still debated whether the matrix inhibition is imputable more to direct virus damage rather than inflammation spreading from skin lesions. ² CLLs related to COVID‐19 infection have been widely documented in mild symptomatic or asymptomatic children and adolescents. ³ Among different pathogenetic hypothesis, the role of cytokine‐mediated inflammatory response and endothelial damage induced by obliterative microangiopathy caused by Sars‐CoV‐2 seem to be the most accredited. ⁴ We assume that, likewise onychomadesis induced by Coxsackievirus, the imbalance between inflammation and direct virus damage could be responsible for nail discharge in our case. ² The acknowledgement of a possible association between CLLs and onychomadesis could avoid unnecessary treatment and reassure the patient's caregivers. Nevertheless, as this is the first documented association in the literature, we suggest that complete history, physical and laboratory examinations should be conducted to rule out other culprit diseases. Until our findings could be further accredited by new observations, dermatologists should be alert to the presentation of onychomadesis as a possible consequence of COVID‐19 chilblain‐like lesions (Fig. 1).

Figure 1.

Onychomadesis of II, III, IV right hand's fingernails (a) and II left hand's fingernail (b).

Conflict of interest

The authors declare no conflict of interest

Funding source

This research received no external funding.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.