Integrative Review: Nummular Eczema – Pathophysiology, Diagnosis, and Treatment

Abstract

Nummular eczema (NE) is a chronic inflammatory dermatosis characterized by coin-shaped pruritic lesions, whose etiology and classification remain challenging. This integrative literature review aimed to elucidate the pathophysiology, diagnosis, and treatment of NE, synthesizing current evidence and therapeutic approaches. The methodology consisted of searching for articles in the BVS and PubMed databases, published between 2020 and 2025, using the descriptor "nummular eczema," resulting in the selection of 10 articles for analysis. The results indicated that epidermal barrier dysfunction and an altered lipid profile are central to the disease, and that therapies targeting the Th2 immune pathway, such as dupilumab, are effective, whereas inhibition of the Th17 pathway with apremilast proved ineffective. The discussion revealed that nummular eczema exhibits a mixed Th2/Th17 immune signature, with Th2 predominance, positioning it as a variant of atopic dermatitis and explaining both the success of dupilumab and the increased risk of psoriasis development during its use. It is concluded that understanding nummular eczema as a Th2-driven disease is fundamental to optimizing diagnosis and treatment, establishing dupilumab as a promising therapy for refractory cases, although clinical monitoring remains essential due to its complex immune signature.

Keywords: Nummular eczema, Atopic dermatitis, Dupilumab, Epidermal barrier dysfunction