COVID-19-induced toxic epidermal necrolysis.

Cutaneous manifestations of COVID‐19 are being increasingly reported in the literature, and include rashes with varying morphology including maculopapular, urticarial, chilblain‐like, vesicular and livedoid/necrotic lesions. To add to this compendium of associations with COVID‐19, we report a patient who developed toxic epidermal necrolysis (TEN) following a positive diagnosis of COVID‐19. We believe this represents a causal association between COVID‐19 and TEN.

A 53‐year‐old woman presented in early December 2020 with a 2‐day history of a maculopapular rash. The patient had metastatic breast carcinoma and since October 2020, she had been an inpatient on the palliative care ward for management of symptoms related to her bone, brain and liver metastases. The rash was a nonblanching, mottled maculopapular rash predominantly affecting her chest, upper back and legs. The eruption had developed 5 days after she had received a positive PCR test for COVID‐19 virus, following development of a new cough. There was no history of any new drugs or any other triggers. Based on this history, the initial diagnosis was that this rash was one of the cutaneous manifestations of COVID‐19 virus. The patient was initiated on a potent topical corticosteroid and emollients and was also closely monitored to see if there was progression of the rash.

Ten days later, the patient developed detachment of the skin on her chest (Fig. 1a), with progression of the rash on the patient’s back, arms, legs, scalp and ears (Fig. 1b). She developed erosions and haemorrhagic crusting of the mouth. The eyes and genitalia were spared. The epidermal detachment affected > 10% of the patient’s surface area. The presentation was in keeping with TEN. The patient's drug history was reviewed again and there was no suggestion of any new medications. Her last chemotherapy cycle had ended 6 months earlier, she had been started on exemestane 5 months earlier, and she was due to start third‐line chemotherapy, but this had been deferred due to her COVID‐19 diagnosis. Her only other new medication was dexamethasone for her brain metastasis, which was continued. The SCORTEN score at the time of the diagnosis was 4 (age, malignancy, initial percentage of epidermal detachment, serum bicarbonate) indicating an expected mortality of > 50%. She had punch biopsies taken from the chest for histology and immunofluorescence. Histology showed full thickness epidermal necrosis supporting the diagnosis of TEN. Immunofluorescence was negative.

Figure 1

Progression of rash: (a) epidermal detachment of chest; (b) maculopapular rash on legs; (c) appearance of rash a week later; (d) full re‐epithelialization.

Owing to her comorbidities, our patient was not transferred to the regional specialist centre, but was managed on the ward by the Dermatology and Palliative Care teams. It was challenging to strike a balance between meeting her palliative needs and the management of her TEN, and the expertise of the Palliative Care team was invaluable. The patient recovered slowly with conservative supportive management (Fig. 1c,d).

There have been many cutaneous manifestations of COVID‐19 reported in the literature. A recent case report suggested possible hydroxychloroquine‐induced TEN in a patient with COVID‐19, but this was not proven by histology. To our knowledge, this is the first report of TEN secondary to COVID‐19. Despite an initial SCORTEN score of 4, our patient improved on conservative therapy, which may indicate that TEN due to COVID‐19 virus is less severe than drug‐induced TEN.