Dermatology, Eastern Virginia Medical School, Norfolk, VA, USA Am J Clin Dermatol (2016) 17:87–97 DOI 10.1007/s40257-015-0169-x 1 Introduction Psoriasis affects more than 7 million adults in the USA [1]. While the prevalence of psoriasis has remained generally stable at approximately 3 % over the past decade [1, 2], the incidence nearly doubled between 1970 and 2000 [3]. Patients with psoriasis report a significant impact on their quality of life, including mental and social function [4–6]. In addition, approximately 30 % of psoriasis patients also develop psoriatic arthritis (PsA) [7–9], which can add to the impact on quality of life, affecting physical function and leading to productivity loss and disability [4, 5, 10, 11]. Because of the chronic, inflammatory nature of psoriasis and PsA, long-term systemic therapy is often necessary to control the signs and symptoms, and to improve physical function and quality of life for patients [7, 12]. Recent reports have identified undertreatment and treatment dissatisfaction as significant barriers to optimal care of psoriasis and PsA patients [9, 13]. The population-based Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) survey of 3426 patients and 781 dermatologists and rheumatologists in North America and Europe was designed to evaluate the diagnosis and ongoing management of patients with psoriasis and PsA from the patient and physician perspectives, as well as evaluating unmet treatment needs. The large volumes of data collected from the study were too extensive to include in a single publication. Results from the global patient and physician MAPP surveys, including the US patient findings, have been published separately [14– 16]. In this report, we explore findings from all US participants, including patients, dermatologists, and rheumatologists, to further investigate similarities and differences in attitudes toward disease severity and treatment, and to identify opportunities to improve the care of patients with psoriasis and PsA. 2 Methods Abt SRBI, Inc. (New York, NY, USA) conducted the MAPP survey between June and August 2012. The study methodology has been reported previously [14, 16]. Briefly, this systematic household telephone survey used random digit dialing to identify a probability sample. Household members aged 18 years or older could participate if they had ever been diagnosed with psoriasis or PsA. Patients did not have to be under the care of a healthcare provider (HCP) at the time of the survey. Dermatologists and rheumatologists were identified through the American Medical Association/American Osteopathic Association national database and were contacted through random sampling methods. Dermatologists were screened to ensure that 50 % or more of their practice was devoted to medical dermatology. 3 Results 3.1 Study Population A total of 1005 patients with psoriasis or PsA were surveyed in the USA; of these patients, 270 (26.9 %) reported a diagnosis of PsA. The mean age of surveyed patients was 57 years, and 61.3 % were female (Table 1). Approximately 75 % of patients reported at least one comorbid condition, with the most commonly reported conditions being general arthritis, hypertension, depression, diabetes, and heart disease. The mean age at symptom onset was 34 years, and the mean age at the time of patients’ psoriasis diagnosis was 37 years. Patients with PsA reported a mean Table 1 Patient demographics and clinical characteristics for the US portion of the Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) survey [15] Characteristic n = 1005b Age (years) Mean age (median) 57 (57) Range (minimum–maximum) 75 (18–93) Females [n (%)] 616 (61.3) Diagnosis of PsA [n (%)]a 270 (26.9) Mean age at onset of psoriasis (years) 34 Mean age at diagnosis of psoriasis (years) 37 Mean age at diagnosis of PsA (years) 44 Comorbidities [n (%)] Arthritis 485 (48.3) Hypertension 430 (42.8) Depression 247 (24.6) Diabetes 183 (18.2) Heart disease 126 (12.5) Cancer 76 (7.6) Other 69 (6.9) Ulcerative colitis 26 (2.6) Liver disease 20 (2.0) Crohn’s disease 14 (1.4) Uveitis 4 (0.4) None 247 (24.6) The copyright for this material is owned by the National Psoriasis Foundation, and this material is reprinted courtesy of the National Psoriasis Foundation PsA psoriatic arthritis a With or without a separate diagnosis of psoriasis b The n value reflects the total number of patients surveyed; the actual number of patients answering each question may vary 88 M. G. Lebwohl et al. interval of 12.4 years between onset of skin symptoms and onset of joint symptoms; the mean age at the time of patients’ PsA diagnosis was 44 years. In the US physician portion of the MAPP survey, 1716 dermatologists and 1235 rheumatologists were screened, and 101 dermatologists and 100 rheumatologists completed the