There is increasing recognition of the distinct clinical and pathological phenotypes associated with each MSA. Most of these features display considerable overlap between MSA groups. Despite this, there are notable differences between the typical combinations of cutaneous and systemic manifestations, response to therapy, prognosis, and disease sequelae that define each dermatomyositis MSA group. The MSAs may ultimately improve diagnosis and sub-classification of dermatomyositis patients. However, more work is needed to understand the pathologic basis for much of the heterogeneity found within these subgroups.

IMPORTANCE Cutaneous disease represents a significant burden for patients with dermatomyositis. However, quantitative estimates of the probability of skin disease remission and clinical factors associated with skin outcomes are lacking.OBJECTIVE To characterize cutaneous disease course in adult patients with dermatomyositis. DESIGN, SETTING, AND PARTICIPANTS Prospective cohort study conducted at a dermatology clinic at a tertiary academic referral center. All adult patients with dermatomyositis (age >18 years) seen between May 15, 2007, and October 28, 2016, were eligible. Patients were included in the current analysis if they had a baseline Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) activity score of 12 or higher, and 2 or more CDASI scores separated by 3 months or more within their first 3 years of follow-up. MAIN OUTCOMES AND MEASURESThe percentage of patients who achieved clinical remission of their cutaneous disease as measured by the CDASI over a 3-year follow-up.RESULTS A total of 74 patients met our inclusion criteria (mean [SD] age at initial CDASI scoring, 54 [13] years; 58 women [78%]), and 28 (38%) achieved clinical remission during our 3-year follow-up period. Increased age (odds ratio [OR], 1.07; 95% CI, 1.02-1.12; P = .01), a dermatomyositis-associated malignancy (OR, 14.46; 95% CI, 2.18-96.07; P = .01), and treatment with mycophenolate mofetil (OR, 6.00; 95% CI, 1.66-21.78; P = .01) were significantly associated with clinical remission of skin disease in multivariable analysis. Patients with anti-melanoma differentiation-associated protein 5 antibodies had a significantly lower probability of meeting outcome criteria in our time-to-event analysis. Baseline cutaneous disease activity, disease duration at baseline, and disease duration before first systemic therapy were not significantly associated with clinical remission of skin disease.CONCLUSIONS AND RELEVANCE Clinical remission was relatively uncommon in our population despite aggressive systemic therapy, and patients with anti-melanoma differentiationassociated protein 5 antibodies were even less likely to enter clinical remission during a 3-year follow-up period. Although mycophenolate mofetil compared favorably with other treatment options, our data provide evidence that a substantial population of patients with dermatomyositis have skin disease that is not adequately managed with standard-of-care therapies.

IMPORTANCEHydroxychloroquine sulfate is a commonly used medication for patients with dermatomyositis and has been associated with a uniquely elevated risk of adverse cutaneous reactions in this population. No studies to date have examined whether certain subsets of patients with dermatomyositis are at increased risk of experiencing a hydroxychloroquineassociated skin eruption.OBJECTIVE To identify disease features that increase the risk of hydroxychloroquineassociated skin eruption in adults with dermatomyositis. DESIGN, SETTING, AND PARTICIPANTSA retrospective cohort study was conducted in the outpatient dermatology clinic at a tertiary academic referral center. All adults with dermatomyositis (age >18 years) who started receiving hydroxychloroquine between July 1, 1990, and September 13, 2016, were eligible for the analysis. Patients were considered to have a hydroxychloroquine-associated skin eruption if a skin eruption had developed within their first 4 weeks of treatment and resolved with discontinuation of hydroxychloroquine therapy.EXPOSURES One or more doses of hydroxychloroquine. MAIN OUTCOMES AND MEASURESThe associations between autoantibodies (against transcription intermediary factor 1γ [TIF-1γ], nucleosome-remodeling deacetylase complex [Mi-2], nuclear matrix protein [NXP-2], small ubiquitinlike modifier 1 activating enzyme [SAE-1/2], melanoma differentiation-associated gene 5 [MDA-5], histidyl-transfer RNA synthetase [Jo-1], Ku, and signal recognition particles) and cutaneous adverse reactions to hydroxychloroquine in patients with dermatomyositis.RESULTS A total of 111 patients met the inclusion criteria, and 23 (20.7%) developed a hydroxychloroquine-associated skin eruption (20 [87.0%] were women with a mean [SD] age of 49 [14] years at diagnosis). Skin eruptions were approximately 3 times more common in patients with anti-SAE-1/2 autoantibodies (7 of 14 [50.0%]) compared with those without the autoantibody (16 of 97 [16.5%]). In contrast, none of 15 patients with anti-MDA-5 autoantibodies had a skin eruption vs 23 of 96 (24.0%) of those without the autoantibody. In exact logistic regressions adjusted for age, race/ethnicity, sex, amyopathic status, anti-Ro52 status, and dermatomyositis-associated cancer, the presence of anti-SAE-1/2 autoantibodies was significantly associated with a hydroxychloroquine-associated skin eruption (odds ratio [OR], 8.43; 95% CI, 1.98-49.19; P = .003) and presence of anti-MDA-5 autoantibodies was significantly negatively associated with a hydroxychloroquine-associated skin eruption (OR, 0.06; 95% CI, 0.0004-0.52; P = .006). No other autoantibodies were significantly positively or negatively associated with a hydroxychloroquine-associated skin eruption.CONCLUSIONS AND RELEVANCE Adverse skin reactions to hydroxychloroquine are relatively common in a US cohort of patients with dermatomyositis. Our data suggest that pathophysiologic differences exist between autoantibody subsets in dermatomyositis.

Background: Common histopathologic findings in cutaneous dermatomyositis include vacuolar interface with dyskeratosis, mucin, and perivascular inflammation. Data examining the relationships between these and other histologic abnormalities, or their dependence on biopsy site, and medications are limited. Methods: Using 228 dermatomyositis skin biopsies and statistical analyses including Chi-squared analyses, calculations of relative risk, and adjusted generalized estimating equation regressions, we investigated relationships between 14 histopathologic findings and the impact of clinical factors on these findings. Results: In biopsies taken from sites of visible rash, interface dermatitis was seen in 91%, and 95% had at least one of perivascular inflammation, mucin, or basal vacuolization. Vascular abnormalities were not closely associated with epidermal or inflammatory findings. Concomitant prednisone significantly decreased the odds of basal vacuolization (odds ratio [OR] = 0.34, 95% confidence interval [CI]: 0.12-0.98, P-value = 0.05), perivascular inflammation (OR = 0.19, 95% CI: 0.07-0.53, P-value = 0.002), and vessel damage (OR = 0.81, 95% CI: 0.68-0.96, P-value = 0.02). Conclusion: Vasculopathy and classic findings of interface dermatitis may be driven by unique pathways in dermatomyositis. Corticosteroid use may impact skin biopsy findings. There is a need for clinicopathologic correlation when diagnosing dermatomyositis. K E Y W O R D S dermatomyositis, dermatopathology, interface dermatitis, vasculopathy

Individuals with epidermolysis bullosa (EB), a group of genodermatoses with skin fragility, often require specialized and expensive bandaging. We analyzed the results from an online survey of 249 EB patients and caregivers living in the United States to investigate the financial impact of EB. Of respondents with severe EB subtypes (recessive dystrophic and junctional), 73% reported a major or moderate financial impact and 26% spent greater than $1000 per month on wound care supplies. These results demonstrate the high financial burden associated with epidermolysis bullosa in the United States and support the need for a federally funded EB bandage program. bandages, dressings, epidermolysis bullosa, finances, genodermatoses, health care delivery, wound care