535 New regional dermatoses during dupilumab therapy for atopic dermatitis

Abstract

Dupilumab is a monoclonal antibody targeting IL-4Ra used for treating atopic dermatitis (AD). A subset of AD patients develops new regional dermatoses (NRDs) on dupilumab therapy. Apart from limited case reports and series, little is known about these NRDs. We conducted a retrospective cohort study at a single academic site to describe the prevalence, clinical features, and management of NRDs among all adults treated with dupilumab for AD. NRDs were defined as eruptions that (1) occur in a new anatomic region, (2) be resistant to usual topicals used, (3) occur on uninterrupted dupilumab therapy, (4) occur following primary therapeutic response, and (5) not be explained by a different entity. Following institutional review board approval, a clinical data warehouse was queried for all adults receiving dupilumab for AD prior to November 1, 2018. 73 patients were included for analysis, of which 17 (23%) had NRDs. 14 had facial rash and 4 had a history of patch test-confirmed allergic contact dermatitis (ACD). The predominant morphologies were eczematous (12/17) and erythema (4/17). Most (11/17) were treated with topical corticosteroids. Four stopped dupilumab due to NRDs. Two NRDs were biopsied: one showed rosacea and the other showed resolving VZV. Two patients with NRDs had negative patch testing to at least 80 allergens within 2 years prior to starting dupilumab. New facial dermatitis while on treatment with dupilumab has been reported and suspected to represent unrecognized ACD. However, ACD likely does not explain all cases, as 2 patients with NRDs in this cohort had negative comprehensive patch testing. Unmasking of another primary dermatosis in an altered cutaneous immune milieu may explain the facial erythema seen in 4 subjects, one of whom had biopsy-proven rosacea. The retrospective study design and lack of diagnostic workup for most NRDs are weaknesses of this study. Larger studies involving biopsy and patch testing are needed to establish their etiology.