Study Links Hypothyroidism to Psoriasis, Independent of Disease Severity

A new cross-sectional study of patients with moderate-to-severe psoriasis undergoing biologic therapy has identified subclinical hypothyroidism as the most common form of thyroid dysfunction in this population. The findings suggest that thyroid abnormalities may represent an independent comorbidity, rather than a direct consequence of psoriasis severity.

The study included adult patients from the psoriasis unit at Hospital Universitario San Cecilio in Granada, Spain, treated with biologics between 2017 and 2023. Patients with mild disease or those on conventional systemic therapies were excluded. Researchers assessed thyroid status using endocrinology records and evaluated psoriasis using the Psoriasis and Severity Index (PASI), body surface area (BSA), Investigator's Global Assessment, Numerical Rating Scale for pruritus severity(, and Dermatology Life Quality Index.

Among the patients analyzed, 4.2% had thyroid dysfunction, all classified as hypothyroidism and most in the subclinical range. Those affected were generally older, with a mean age of 57.4 years. Importantly, no statistically significant differences were found in psoriasis severity or treatment response between patients with and without thyroid dysfunction.

“Our findings suggest hypothyroidism is the main thyroid dysfunction in psoriatic patients, independent of psoriasis severity,” the authors reported.

The study did not demonstrate a clear correlation between elevated PASI or BSA scores and the presence of hypothyroidism. This raises the possibility that shared inflammatory pathways rather than disease severity or immune suppression from biologics may link psoriasis and thyroid dysfunction.

“The lack of impact on psoriasis severity suggests hypothyroidism may be an independent comorbidity, warranting further research into shared inflammatory mechanisms,” the authors concluded.

For practicing dermatologists, these findings support a proactive approach to screening for thyroid dysfunction, particularly in older patients with moderate-to-severe psoriasis. While thyroid abnormalities may not influence psoriasis treatment response or severity, their identification and management may contribute to overall patient health and improved comorbidity surveillance.

Reference
Ruiz-Villaverde R, Cebolla-Verdugo M, Llamas-Segura C, Ezomo-Gervilla PJ, Molina-Espinosa J, Ruiz-Carrascosa JC. Subclinical hypothyroidism in moderate-to-severe psoriasis: a cross-sectional study of prevalence and clinical implications. Diseases. 2025;13(8):237. doi:10.3390/diseases13080237