joint symptoms. In addition, 37.6 % of dermatologists most often cited differentiating PsA from other arthritic diseases as the greatest challenge in managing PsA patients, while 25.0 % of rheumatologists cited delayed referral as one of their greatest challenges. 3.4 Physician Attitudes: Challenges in Patient Management Both dermatologists and rheumatologists reported that the management of patients with psoriasis and PsA can be challenging. According to 68.3 % of the dermatologists, their psoriasis patients require more time and support than patients with other medical concerns, with 24.8 % reporting management of psoriasis patients as complicated and 34.7 % reporting it as time consuming. In addition, 32.7 % of dermatologists reported that managing patients with PsA was complicated, while 26.7 % of dermatologists said that managing these patients was time consuming. However, only 6.9 % of dermatologists thought they would need to refer to or involve other specialists in the care of their PsA patients (and only 1 % thought they would need to involve other specialists in the care of their psoriasis patients). Of the rheumatologists surveyed, 23 % reported that their PsA patients require more time and support than their other patients. In addition to the challenges of differentiating PsA from other arthritic conditions, dermatologists also cited challenges with the therapies for psoriasis and PsA, such as affordability (28.7–57.4 %), lack of long-term safety (8.9–16.8 %), and lack of effectiveness (12.9–14.9 %). Similarly, in addition to delayed referral, rheumatologists most often cited affordability (39 %), lack of effectiveness Fig. 1 Top five most important factors contributing to disease severity in psoriasis (a) and psoriatic arthritis (b), as reported by patients and physicians 90 M. G. Lebwohl et al. (19 %), and lack of long-term safety (9 %) of current medications as the greatest challenges in treating PsA patients. 3.5 Medical Care and Treatment Patterns 3.5.1 Patient Use of Medical Care Among the psoriasis patients, 42.6 % reported that they had not seen an HCP in the previous 12 months. Of the 57.4 % of psoriasis patients who had seen an HCP in the previous 12 months, 56.9 % had seen a dermatologist and 30.2 % had seen a primary care physician (Table 3). The most common reasons that psoriasis patients cited for not seeing an HCP were that the symptoms were not bad enough, there were no symptoms, they did not think an HCP could help, the current treatment was working, or they were unable to get an appointment (Table 3). In contrast, the majority of PsA patients (85.6 %) had seen an HCP in the previous 12 months; these patients reported most often seeing a rheumatologist for their PsA, followed by a primary care physician and a dermatologist (Table 3). The reasons cited by PsA patients for not seeing an HCP in the previous year generally were similar to those cited by psoriasis patients, including that their symptoms were not bad enough, they did not think an HCP could help, there were no symptoms, the current treatment was working, and the cost or lack of insurance (Table 3). 3.5.2 Current Treatments Overall, patients reported lower rates of current treatment than dermatologists and rheumatologists, with substantial differences noted in use of biologic therapy by psoriasis and PsA patients and use of conventional oral therapy by PsA patients (Tables 4, 5). Fewer than 10 % of psoriasis patients reported use of conventional oral therapy or biologic therapy, compared with approximately 25 % of PsA patients reporting use of each treatment. While 50 % of PsA patients reported use of systemic therapy, half reported no treatment or reported use of topical medications only, leaving their joint disease untreated. According to the physicians surveyed, use of conventional oral and biologic therapies was much higher than that reported by patients. Dermatologists reported use of conventional oral therapy in 12.7 % of their psoriasis patients and 22.9 % of their PsA patients, while rheumatologists reported use in 57.1 % of PsA patients. Dermatologists reported use of biologic therapy in 35.8 % of psoriasis patients and 46.9 % of PsA patients, while rheumatologists reported use of biologic therapy in 52.7 % of PsA patients. Some of these discrepancies in reported treatment rates probably arose because patients were not required to be seeing an HCP or receiving treatment to participate in the MAPP survey. However, even the proportion of physician-reported treatment indicates a level of undertreatment. 3.6 Treatment Challenges and Burdens 3.6.1 Conventional Oral Therapy Of the 250 respondents who had ever used conventional oral therapies, about half found them burdensome. The reasons for the treatment burden most often cited by Table 3 Previous and current medical care in