Superficial erythema annulare centrifugum – clinico-morphological correlation: case report

Abstract

Erythema annulare centrifugum (EAC) is a chronic inflammatory disease, of unclear etiology, it can be associated with various infections, autoimmune processes, malignant neoplasms, etc. Recent studies have highlighted an incidence of 1 case per 100,000 population per year of EAC.[1] Clinically: EAC is characterized by the formation of annular or polycyclic plaques, with a pale pink central area with peripheral scaling. Superficial and deep forms are differentiated histopathologically. Superficial EAC: develops clinically with the formation of trailing scale, a fine collarette on the inner side of the erythematous border of the eruption, without induration, accompanied by itching; the histopathological examination reveals - spongiosis, parakeratosis at the level of the epidermis and in the superficial dermis - perivascular lymphocytic infiltrate. Deep EAC goes along without pruritus, the eruption with an indurated periphery, without scales; histologically - no changes in the epidermis, but intense perivascular lymphohistiocytic infiltrate in the dermis can be seen. The treatment is based on the use of systemic and topical corticosteroids, calcineurin inhibitors, vitamin D analogues; for the treatment of underlying diseases - antibiotics (macrolides), antimicrobial agents (metronidazole) and antifungals. Objective of the study Highlighting the clinico-morphological correlation in a rare case of superficial EAC. Case report: The clinical case study of superficial EAC concerns a 55-year-old female patient with lesions on the trunk, upper and lower limbs and a 5-month history of the disease. The clinical examination revealed: multiple pink papules with centrifugal extension and formation of annular, polycyclic plaques, an insignificant elevation and desquamation of the internal border, accompanied by moderate, permanent itching. Paraclinical examination: fungal infection was ruled out. The histopathological examination confirmed: EAC superficial type, highlighting parakeratosis, hyperkeratosis, minimal spongiosis, involving the lower part of the epidermis; in the superficial dermis - moderately expressed perivascular lymphohistiocytic inflammatory infiltrate. Systemic treatment included corticosteroids and antibiotics (macrolides), topical - corticosteroids of medium potency. Discussions In the presented case, associated systemic diseases and precipitating factors were not identified. To make the differential diagnosis, several conditions were taken into consideration, such as tinea corporis, granuloma annulare, erythema gyratum repens, erythema marginatum. The presence of moderate itching and the trailing scale on the clinical examination, as well as the results of the histopathological examination, made it possible to establish the diagnosis of superficial EAC. The treatment performed (systemic corticotherapy, associated with erythromycin) led to the total involution in the dynamics of the skin lesions and the absence of recurrences during 1 year of monitoring. Conclusions Strong correlation between clinical appearance and histopathological changes identified in a rare case of superficial EAC was demonstrated. There are studies [2], which attest the fact that superficial type EAC is a more refractory form to usual treatments and the recurrence rate is high. The presented case marks a good prognosis, taking into account the excellent response to the indicated treatment and the absence of recurrences over a long period.