Atypical erythema multiforme palmar plaques lesions due to Sars‐Cov‐2

Dear Editor,

Since coronavirus disease 19 (COVID‐19) was declared as a pandemic, all medical specialties were at the front, including dermatology. Daily, there are observations mentioning possible cutaneous manifestations of SARS‐CoV‐2.

Among these manifestations, the most often was a rash which could be erythematous, morbilliform or urticarial mimicking viral exanthema, or chickenpox‐like vesicles. ¹ , ² , ³ Anecdotally, dengue‐like petechial eruption was reported. ⁴ Some dermatology societies have alerted health professionals to the possibility of acral involvement such as ischaemia and livedo in the context of thromboembolic manifestations of COVID‐19. Recently, a case of COVID‐19 infection‐induced chilblains was reported with histopathological findings showing lichenoid, perivascular and peri‐eccrine infiltrate of lymphocytes associated with necrotic keratinocytes. ⁵

We report two patients with diagnosis of COVID‐19 presenting erythema multiforme (EM) lesions which could be another acral cutaneous manifestation due to SARS‐CoV‐2.

First case is a 17‐year‐old adolescent with no medical history, documented to have a mild SARS‐CoV‐2 infection for which he took vitamin C only. On the 15th day of the onset of symptoms, he developed erythematous maculopapular atypical targetoid eruption of palms only ( Fig.  1 ). Lesions were painless and mild itching. There was no mucosal involvement. No recent episode of recurrent herpes was reported.

Figure 1.

Erythematous maculopapular atypical targetoid eruption of palms.

Second case is a 29‐year‐old man with no past medical history had been diagnosed with COVID‐19 and treated by hydroxychloroquine associated with azithromycin. He developed fixed and asymptomatic erythematous urticarial targetoid lesions on his palms ( Fig.  2 ). He had started taking medication 3 days before rash, and COVID‐19 symptoms had started 12 days earlier. Hydroxychloroquine and azithromycin were continued, and palm eruption was progressively disappeared.

Figure 2.

Fixed and asymptomatic erythematous urticarial targetoid lesions of palm.

Erythema multiforme is immune‐mediated reaction that involves the skin and sometimes the mucosa due to infections, especially herpes simplex virus and mycoplasma pneumonia (MP), and medications like hydroxychloroquine. It consists of a polymorphous eruption of macules, papules and characteristic ‘target’ lesions that are symmetrically distributed with a propensity for the distal extremities. Histological findings are apoptotic individual keratinocytes and perivascular lymphocytic infiltrate in the papillary dermis and along the dermo‐epidermal junction.

Mycoplasma pneumonia‐related EM has a distinctive presentation compared with non‐MP EM, with more diffuse and atypical targets, more mucositis and respiratory tract sequelae. ⁶ EM is a rare hydroxychloroquine‐induced cutaneous adverse reaction with generalized distribution involving trunk, abdomen, back and mucosa. ⁷ On another side, palmar plaques should suggest syphilis, especially in young people. ⁸ Both of our patients had localized acral targetoid lesions with no mucosal involvement and a negative syphilitic serology. This clinical presentation associated with chronology and evolution of eruption was suggestive of a SARS‐CoV‐2‐related EM rather than other causes particularly hydroxychloroquine or MP. Pathophysiological mechanism could be a hypersensitivity reaction lymphocyte cells mediated with pro‐inflammatory cytokines production targeting SARS‐CoV‐2 antigens present in skin. Limitation of our observations was a lack of histology and MP serology. Further studies are expected to validate our findings.

Acknowledgement

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