Characterization of clinical photosensitivity in cutaneous lupus erythematosus

• Published in: Journal of the American Academy of Dermatology 2013-08, Vol.69 (2), p.205-213
• Main Authors: Foering, Kristen, MD, Chang, Aileen Y., MD, Piette, Evan W., MD, Cucchiara, Andrew, PhD, Okawa, Joyce, RN, Werth, Victoria P., MD
• Format: Article
• Language: English
• Subjects: Adult; Biopsy, Needle; Cohort Studies; cutaneous lupus erythematosus; dendritic cells; Dermatology; Female; Follow-Up Studies; Humans; Immunohistochemistry; Logistic Models; Lupus Erythematosus, Cutaneous - diagnosis; Lupus Erythematosus, Cutaneous - epidemiology; Lupus Erythematosus, Cutaneous - genetics; Male; Middle Aged; Multivariate Analysis; Phenotype; photosensitivity; Photosensitivity Disorders - diagnosis; Photosensitivity Disorders - epidemiology; Photosensitivity Disorders - genetics; polymorphic light eruption; Prevalence; Prospective Studies; Self Report; Severity of Illness Index; Statistics, Nonparametric; Sunlight - adverse effects; Surveys and Questionnaires; systemic lupus erythematosus
• ISSN: 0190-9622; 1097-6787
• DOI: 10.1016/j.jaad.2013.03.015

Background Photosensitivity (PS) in lupus erythematosus (LE) is frequently determined by patient report. Objective We sought to characterize self-reported PS in cutaneous LE (CLE). Methods The PS survey was used to classify subject responses into 5 phenotypes: direct sun-induced CLE flare (directCLE); general exacerbation of CLE (genCLE); polymorphic light eruption–like reactions (genSkin); general pruritus/paresthesias (genRxn); and sun-induced systemic symptoms (genSys). In all, 91 subjects with CLE alone or with CLE and systemic LE were interviewed. Results In all, 81% ascribed to 1 or more PS phenotypes. CLE-specific reactions (direct sun-induced CLE flare or general exacerbation of CLE) were reported by 86% of photosensitive subjects. Higher CLE disease activity (measured by CLE Disease Area and Severity Index activity scores) was suggestive of direct sun-induced CLE flare reactions ( P  = .09). In all, 60% of photosensitive subjects described CLE-nonspecific reactions: polymorphic light eruption–like rash and general pruritus/paresthesias. These phenotypes often co-occurred with CLE-specific reactions and were predicted by more systemic disease activity as measured by Physicians Global Assessment (PGA) scores in regression analyses (genSkin, P  = .02) and (genRxn, P  = .05). In all, 36% of subjects reported systemic reactions and higher PGA scores were predictive of the sun-induced systemic symptoms phenotype ( P  = .02); a diagnosis of systemic LE was not ( P  = .14). Limitations PS was inferred from patient report and not directly observed. Conclusions Characterization of self-reported PS in LE reveals that patients experience combinations of CLE-specific, CLE-nonspecific, and systemic reactions to sunlight. Sun-induced CLE flares are associated with more active CLE disease. Polymorphic light eruption–like, generalized pruritus/paresthesias, and systemic reactions are associated with more active systemic disease. Recognition of PS phenotypes will permit improved definitions of clinical PS and allow for more precise investigation into its pathophysiology.