Acro‐ischaemia in hospitalized COVID‐19 patients

Dermatological manifestations of the coronavirus disease 2019 (COVID‐19) may include unspecific macular erythematous rash, urticarial lesions and chickenpox‐like vesicles. ¹ , ² Acro‐ischaemic lesions have been described in two different types of COVID‐19 patients: firstly critically ill patients with severe limb ischaemia and secondly paucisymptomatic young patients with chilblain‐like lesions. ³ The aetiopathogenesis and clinical implications of these lesions remain unclear.

This letter reports three cases admitted to our hospital with bilateral pneumonia during the COVID‐19 pandemic in Madrid (Spain), who developed acral ischaemic lesions during their hospitalization period. All three patients presented with atypical bilateral pneumonia and positive nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Physical examination revealed rounded reddish‐purple plaques, measuring between 0.5 and 1 cm, sharply defined, with no retiform borders (Fig. 1a,b). Toes were affected in all three cases, and soles were affected in one of them. Palms and mucous membranes were not altered. Time from the onset of respiratory symptoms to skin acro‐ischaemia was 17, 24 and 28 days. D‐dimer was elevated in the three of them and fibrinogen in two, but no other coagulation abnormalities were detected. There were no signs of multiorgan dysfunction and no vasoactive drugs were used. None of the patients had a fatal outcome. Skin lesions fully recovered in a two‐week period. Histological examination showed ischaemic necrosis affecting the epidermis and dermis with signs of re‐epithelialization. Vasculitis or microthrombi were not found after reviewing extensive deep sections (Fig. 2).

Figure 1.

(a) Two red macules and one purple macule, subcentimetrics, on the plantar side of the left feet. This patient was the only one who referred occasional mild discomfort. (b) Reddish‐purple oval plaque on the first toe.

Figure 2.

Acral skin that shows an intra‐epidermal vesicle. It has ischaemic necrosis on its roof, containing preserved cell outlines without nuclei, and reticular changes. The vesicle is associated with an acute inflammatory infiltrate. The dermis shows dilated vessels (H&E stain; x4).

Coagulation parameters in SARS‐CoV‐2‐infected patients are often altered. ⁴ , ⁵ D‐dimer is the most common laboratory abnormality and appears to be related to mortality. ⁶ Zhang et al. ⁴ reported a case series of seven patients with critical COVID‐19 pneumonia and acro‐ischaemia, accompanied by significant elevation of D‐dimer, fibrinogen and abnormal coagulation function (mainly prolonged prothrombin time). This could be explained by the cytokine storm triggered by the virus, which would lead to an undesirable activation of the coagulation cascade and the development of microthrombi. ⁷ However, histological examination in our patients did not show vasculopathic features.

We would like to underscore that acro‐ischaemia was not the reason for dermatologic consultation. These asymptomatic types of lesions, similar to the ones seen in the paediatric population, are probably underreported. Physicians should be aware of acro‐ischaemic lesions, as they could be associated with systemic involvement and benefit from anticoagulation therapy in the hospitalized patient.

In conclusion, we would like to highlight that self‐healing acro‐ischaemic lesions can also appear in hospitalized COVID‐19 patients. It would seem that there is a continuum spectrum related to acro‐ischaemic lesions, ranging from mild chilblain‐like lesions to dry gangrene. Whether these lesions are associated with prognostic factors or have therapeutic implications needs to be elucidated.

Acknowledgement

The patients in this manuscript have given written informed consent to the publication of their case details.