Erythema annulare centrifugum triggered by SARS-CoV-2 infection.

Erythema annulare centrifugum (EAC) is a reactive phenomenon of the skin that has been reported to occur in association with numerous conditions, including infections. It commonly presents with annular, erythematous plaques with a fine desquamation in the inner portion of the advancing edge. In the last year, a wide spectrum of cutaneous manifestations has been associated with SARS‐CoV‐2 infection, including acral areas of erythema with vesicles or pustules, other vesicular eruptions, urticarial lesions, maculopapular eruptions and livedo or necrosis. ,

A 37‐year‐old otherwise healthy woman presented with a 1‐week history of itching skin lesions on the arms and back. She referred history of fever, headache and malaise 2 weeks before the onset of these lesions. A nasopharyngeal reverse transcription‐polymerase chain reaction (RT‐PCR) was positive for SARS‐CoV‐2 at that time. Physical examination revealed multiple erythematous papules and annular plaques with central clearing and a delicate scale on the inner margin on the upper arms and back (Fig. 1). Potassium hydroxide test was negative. Histopathology showed a prominent perivascular lymphocytic infiltrate on papillary dermis and occasionally on reticular dermis, with endothelial tumefaction, hematic extravasation and sparse interstitial eosinophils (Fig. 2). Clinicopathologic findings were compatible with EAC. A routine laboratory work‐up had no alterations. Treatment with clobetasol propionate 0.05% cream was applied once daily for 2 weeks with completely resolution of the lesions.

Figure 1

Multiple erythematous papules and annular plaques with a trailing scale on the upper arms.

Figure 2

Prominent perivascular lymphocytic infiltrate on papillary dermis in a ‘coat sleeve’ appearance with endothelial tumefaction, hematic extravasation and sparse interstitial eosinophils.

EAC is a gyrate erythema characterized by erythematous papules that expand centrifugally with central clearing resulting in annular plaques. Typically, a fine scale is present in the inner portion of the advancing edge, known as trailing scale. Pruritus is variable, and the most frequent localizations are the trunk and lower extremities. EAC is thought to be a delayed‐type hypersensivity response to a wide variety of antigens. Possible triggers may include viral, bacterial or fungal infections, medications, foods, malignancy or other systemic diseases. , , However, in many patients, a specific trigger cannot be recognized. Histopathologic findings in EAC consist of a dense perivascular lymphocytic infiltrate on papillary dermis and possibly reticular dermis, which is known as a ‘coat sleeve’ appearance. Variable oedema, spongiosis, parakeratosis and basal layer vacuolization may be present. Differential diagnosis includes other skin disorders that may present with annular, erythematous lesions such as erythema migrans, tinea, pityriasis rosea, psoriasis, granuloma annulare and annular lupus erythematosus. ,

In our case, the typical clinic and histopathologic findings of EAC together with SARS‐CoV‐2 infection confirmed by a RT‐PCR 2 weeks before supported the theory of a possible association. EAC has been suggested to be a tumour necrosis alpha (TNF‐alpha) dependent process. Therefore, the proinflammatory cytokines released during SARS‐CoV‐2 infection could be involved in the pathogenesis of EAC.

To our knowledge, there is only one previous report of EAC presumptive triggered by SARS‐CoV‐2. The patient presented with clinical and histopathological skin lesions consistent with EAC accompanied by anosmia and ageusia that completely resolved with doxycycline. However, a RT‐PCR was not obtained at that time and diagnosis of SARS‐CoV‐2 was made two months later based on a serological screening test.

Usually, EAC has a self‐limited course and good prognosis. Data on treatment for EAC are sparse. Topical corticosteroids, topical vitamin D analogues, metronidazole, macrolides (azithromycin, erythromycin), fluconazole and etanercept have been reported to be useful in some cases. , ,

We report the second case of EAC probably triggered by SARS‐CoV‐2 in a patient with confirmed infection by nasopharyngeal RT‐PCT 2 weeks before the onset of the cutaneous lesions that completely resolved with clobetasol propionate 0.05% cream.

Conflict of interest

All the authors declare no conflict of interest.

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