Long-Term Outcomes of Patients with Biologically Treated Psoriatic Arthritis and Atopic Dermatitis—A Single-Center Experience

(1) Background: Although the association between psoriasis and atopic dermatitis (AD) is reported in the literature, scarce data are known about the efficacy of biologic therapy (including TNF and IL-17 inhibitors) in patients with psoriatic arthritis (PsA) and concomitant AD. (2) Objective: We aimed to explore AD in patients with PsA undergoing biologics for their active disease, focusing on prevalence and clinical and potential therapeutic implications. (3) Material and methods: We performed a retrospective analysis of 64 patients with PsA receiving various biological agents, followed-up in an academic outpatient rheumatology department up to 10 years. (4) Results: Atopic diseases were reported in about one third of cases, with a higher incidence of AD (10 cases; 52.6%) vs. atopic rhinitis (6 cases; 31.6%) and allergic asthma (3 cases; 15.8%). Three morphological patterns of AD were recognized including chronic prurigo (3 cases), a chronic lichen simplex (1 case), and eczemas (6 cases). All PsA with concomitant AD displayed a late onset of skin atopy (in their adult life) and demonstrated a specific profile (younger), from urban settings, equally distributed among genders, and requiring switching to a higher number of biologics to achieve disease control. (5) Conclusion: PsA and AD may coexist, requiring special attention when selecting the optimal biologic agent.