Psoriasis With Eczematous Features: A Retrospective Clinicopathologic Study

BACKGROUND: Dermatopathologists sometimes encounter patients with features of psoriasis vulgaris and additional changes of eczematous dermatoses. These cases are challenging to diagnose, and the clinical implications are unclear. In the age of targeted therapy, it is important to improve our understanding of these findings so that patients are managed appropriately. OBJECTIVE: To characterize the clinical characteristics, histopathological features, diagnostic workup, successful treatment, and outcomes of patients with overlapping histopathologic features of psoriasis vulgaris and eczema. METHODS: We conducted a retrospective chart review of 20 patients who had received the histopathologic diagnosis of psoriasis vulgaris with eczematous changes noted on skin biopsy. A database that included information about clinical characteristics, comorbidities, histopathological features, diagnostic workup, treatment modalities, and outcomes was created and analyzed. RESULTS: Twenty patients were included in this study, with an average age of 57.3 years. After clinicopathologic correlation, most patients were diagnosed with psoriasis (85%), and the remainder were determined to have an eczematous dermatitis. Thirty-five percent of patients were diagnosed with allergic contact dermatitis, either in combination with psoriasis (6 patients) or alone (1 patient). Topical glucocorticoids were the most common effective therapy used, and systemic therapies were required in nearly half of patients for successful treatment. CONCLUSION: This study offers insights into the clinically and histopathologically challenging diagnosis of psoriasis vulgaris with eczematous changes and offers the diagnostic term "eczematized psoriasis" to describe these patients. The presence of allergic contact dermatitis should be considered in these patients.