Increased risk of incident thyroid diseases in people with psoriatic disease: A cohort study.

BACKGROUND: The association between psoriasis and thyroid diseases was unclear.

OBJECTIVE: To examine the risk of thyroid diseases in psoriasis patients.

METHODS: We used Taiwan's National Health Insurance Research Database to conduct a nationwide cohort study. We examined the hazard ratio (HR) and 95% confidence interval (CI) for incident thyroid diseases in relation to psoriasis and psoriatic arthritis.

RESULTS: We identified 13,266 patients with psoriatic arthritis (psoriasis arthritis group), 149,576 with psoriasis alone (psoriasis group), and 162,842 nonpsoriatic controls. When compared to nonpsoriatic controls, the psoriasis arthritis and psoriasis groups had an increased risk of incident hyperthyroidism (adjusted HR: 1.32 (95% CI 1.07-1.65) and 1.22 (95% CI 1.11-1.33), respectively) and Grave's disease (adjusted HR: 1.38 (95% CI 1.07-1.79) and 1.26 (95% CI 1.13-1.41), respectively). Both groups had an increased risk of incident hypothyroidism (adjusted HR: 1.74 (95% CI1.34-2.27) and 1.38 (95% CI 1.23-1.56), respectively) and Hashimoto's thyroiditis (adjusted HR: 2.09 (95% CI 1.34-3.24) and 1.47 (95% CI 1.18-1.82), respectively).

LIMITATIONS: Lack of data on psoriasis severity.

CONCLUSION: People with psoriatic disease are associated with increased incident thyroid diseases including hyperthyroidism, hypothyroidism, thyroiditis, Grave's disease, and Hashimoto's thyroiditis. Endocrinological consultation may be considered when psoriasis patients present with thyroid symptoms.