to the burden of these therapies. Opinions on the barriers to use of biologic therapy differed among patients and physicians. Patients reported anxiety about and preparation of injections as the most common reasons for therapy being burdensome, and concerns with safety and tolerability or lack of effectiveness as reasons for discontinuation, while dermatologists and rheumatologists cited lack of long-term safety and cost as the most common reasons for not initiating or continuing biologic therapy. The discrepancy in the importance of cost to patients and physicians may reflect the effort required to determine insurance eligibility and ensure reimbursement before prescribing, which falls heavily on physicians versus patients, thus cost may not be considered an issue by patients. The reasons for treatment discontinuation are generally consistent with those found in a report of 1095 patients with moderate to severe psoriasis treated in dermatology clinics within the USA [22]. A survey of NPF members also found a high rate of dissatisfaction with treatment among psoriasis patients (52.3 %) and PsA patients (45.5 %), and cited adverse effects and efficacy as the main reasons for patient discontinuation of biologic therapy, along with inadequate insurance coverage and cost [13]. Overall, the results of the MAPP survey among the US respondents were consistent with those of global respondents; however, some differences among physicians and patients were noted. For patients with moderate to severe psoriasis, a higher proportion of US dermatologists reported treating patients with biologic therapies, compared with dermatologists globally (35.8 versus 19.6 %, respectively) [16]. Likewise, higher proportions of US dermatologists and rheumatologists reported treating PsA patients with biologic therapies, compared with dermatologists and rheumatologists globally (46.9–52.7 versus 30.6–33.4 %) [16]. The challenges of managing psoriasis and PsA patients identified by US physicians and global physicians were similar; however, affordability of therapies was considered a treatment challenge for psoriasis and PsA by a greater proportion of US physicians than global physicians MAPP Survey Results from US Patients and Physicians 95 (28.7–57.4 % for US physicians versus 22.0–36.1 % for global physicians) [16]. Survey responses among US patients generally reflected those of the global population. Differences between US patient responses and global patient responses to the MAPP survey have been reviewed previously; these include a higher proportion of US patients than global patients reporting comorbidities such as arthritis (48.3 versus 34.4 %) and hypertension (42.8 versus 32.7 %) [14, 15]. Treatment patterns reported by US and global patients were generally similar, as were the reasons identified for treatment discontinuation or for not initiating treatments. The findings from the MAPP survey are limited by survey-related factors, which include lack of a control group and reliance on accurate recall and interpretation of questions. Because the survey was blinded, respondents could not be contacted again to follow up or clarify answers. Although patients and physician results are compared within this report, the patients and physicians were not matched, and the survey was not designed to directly compare specific disease or treatment differences. 5 Conclusion The findings from the US MAPP survey population highlight the differences in perceptions between physicians and patients with psoriasis and/or PsA regarding disease severity and the impact on treatment choices. Patients with psoriasis consistently reported that itching, which is usually not captured in current assessment tools, is the most influential factor in determining psoriasis severity, whereas physicians reported the size or location of lesions as leading factors contributing to disease severity. Psoriasis patients should be screened and assessed routinely for symptoms of PsA, and dermatologists need tools to differentiate PsA from other rheumatic diseases. These enhancements, along with improving referral rates and collaboration between dermatologists and rheumatologists, may lead to improved treatment of psoriasis and PsA. Ongoing communication between patients and physicians is needed for better understanding of perceptions of disease severity, discussion and agreement on treatment options, and establishment of realistic treatment goals. The need for safe, effective, and easy-to-use therapies for both psoriasis and PsA remains. Compliance with Ethical Standards Mark G. Lebwohl is an employee of the Mount Sinai Medical Center, which receives research funds from Amgen, Anacor, Aqua, Canfite Biopharma, Celgene, Clinuvel, Coronado Biosciences, Eli Lilly, Ferndale, Janssen Biotech, LEO Pharma,