Psoriasis may express as active severe disease or as mild stable disease. In particular, patients with active severe disease present systemic involvement, including comorbidities and increased values of parameters reflecting an active state of innate immunity. In contrast, patients with mild stable disease show a dominancy of acquired immunity. In this review article, we report the clinical aspects of disease manifestations of both active and quiescent psoriasis as well as the immunological aspects, as well as the impact on antimicrobial resistance. The activity of psoriasis is not captured in the present outcome measures for severity assessment. The present review suggests that incorporating disease activity may be important in the assessment of the efficacy of treatments.