High prevalence of thyroid dysfunction in patients with generalised pustular psoriasis

Takeaway

• The prevalence of thyroid dysfunction was higher in patients with generalised pustular psoriasis (GPP).
• Psoriatic patients with thyroid dysfunction showed significantly higher Psoriasis Area and Severity Index (PASI) scores and higher serum C-reactive protein (CRP) levels vs those without.

Why this matters

• Findings indicate that thyroid dysfunction in psoriatic patients is associated with inflammation caused by psoriasis.

Study design

• 85 patients with psoriasis vulgaris (PsV; n=51), psoriatic arthritis (PsA; n=23) and GPP (n=11) were included.
• The prevalence of thyroid dysfunction and association between the severity of psoriasis and serum free triiodothyronine (fT3), free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels were evaluated.
• PASI and clinical assessment part of the Disease Activity Score with 28 joints (DAS28) score were evaluated using CRP.
• Funding: None disclosed.

Key results

• Of 85 patients, 12 (14.1%) had thyroid dysfunction.
• Patients with GPP had a higher prevalence of thyroid dysfunction vs those with PsA (45% vs 13%; P=.0037) and PsV (45% vs 8%; P=.0348).
• Patients with vs without thyroid dysfunction had significantly higher PASI scores (21.0±3.2 vs 13.5±1.2 [Shapiro-Wilk test, P<.0001; Wilcoxon rank sum test, P=.0151]) and serum CRP levels (5.56±2.98 vs 0.73±0.25 [Shapiro-Wilk test, P<.0001; Wilcoxon rank sum test, P=.0069).
• PsA patients with vs without thyroid dysfunction had:
  • higher PASI scores (11.8±3.0 vs 7.8±1.2); and
  • lower serum CRP levels (0.07±0.02 mg/dL vs 0.39±0.16 mg/dL) and DAS28 scores (1.28±0.90 vs 2.95±0.46).
• A significant negative association was observed between the serum levels of CRP and fT3 (r=−0.4635; P=.0032).
• No significant association was observed between serum levels of CRP and TSH (r=−0.0504; P=.1777) and CRP and fT4 (r=0.1242; P=.0181).

Limitations

• Small number of psoriatic patients with thyroid dysfunction.