Environmental risk factors for the development of psoriatic arthritis: results from a case–control study

• Published in: Annals of the rheumatic diseases Vol. 67; no. 5; pp. 672 - 676
• Main Authors: Pattison, E, Harrison, B J, Griffiths, C E M, Silman, A J, Bruce, I N
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and European League Against Rheumatism 01.05.2008; BMJ; Elsevier Limited
• Subjects: Adult; Age of Onset; Arthritis, Psoriatic - etiology; Arthritis, Psoriatic - psychology; Arthritis, Reactive - etiology; Arthritis, Reactive - psychology; Bacterial Infections - complications; Biological and medical sciences; Case-Control Studies; Dermatology; Diseases of the osteoarticular system; Female; Fractures, Bone - complications; Hepatitis; Hormone replacement therapy; Humans; Immunization; Infections; Inflammatory joint diseases; Life Change Events; Literature reviews; Logistic Models; Male; Medical sciences; Middle Aged; Oral Ulcer - complications; Pregnancy; Psoriasis; Psoriasis - complications; Psoriasis - psychology; Psoriasis. Parapsoriasis. Lichen; Psoriatic arthritis; Questionnaires; Response rates; Retrospective Studies; Risk Factors; Rubella Vaccine - administration & dosage; Self report; Trauma; United Kingdom > UK; England; Spondylarthropathy; Skin disease; Chronic; Psoriasis; Diseases of the osteoarticular system; Risk factor; Rheumatology; Environmental factor; Inflammatory joint disease; Case control study; Psoriatic arthritis
• ISSN: 0003-4967; 1468-2060; 1468-2060
• DOI: 10.1136/ard.2007.073932

Objective:To identify potential risk factors for the onset of inflammatory arthritis (IA) in a large cohort of patients with psoriatic arthritis (PsA) of recent onset.Methods:We recruited cases with psoriasis and an onset of IA within the past 5 years. Controls were patients who had psoriasis but no arthritis. We assessed potential factors associated with the development of IA using a detailed postal questionnaire. An unmatched analysis adjusted for age and gender was performed. Exposure was censored in the controls at a “dummy-date” assigned randomly in proportion to the percentage of cases developing IA in any given year.Results:We studied 98 cases and 163 controls. Exposures showing a positive association before the onset of IA in patients with psoriasis were: rubella vaccination (OR (95% CI) = 12.4 (1.2 to 122)), injury sufficient to require a medical consultation (2.53 (1.1 to 6.0)), recurrent oral ulcers (4.2 (2.0 to 9.0)) and moving house (2.3 (1.2 to 4.4)). Cases were also more likely to have experienced a fractured bone requiring hospital admission (50% vs 9%, p = 0.040).Conclusions:We found a number of environmental exposures associated with the onset of IA in subjects with psoriasis. The strongest associations were with trauma thereby adding to the hypothesis of a “deep Koebner phenomenon” in PsA. Our data also suggest that exposure of the immune system to certain infection-related triggers may also be of relevance. Further studies are needed to verify these observations and to examine potential immunological mechanisms that underlie them.