POLYMORPHOUS LIGHT ERUPTION AND ITS ASSOCIATION WITH HYPOTHYROIDISM AND AUTOIMMUNE THYROIDITIS – A COMPARATIVE CROSS-SECTIONAL STUDY

Abstract

BACKGROUND In many parts of the world, polymorphous light eruption (PLE) is the commonest cause of photosensitivity. Previous studies have suggested the association of PLE with multiple autoimmune diseases. Few studies are available suggesting the association of PLE with autoimmune thyroiditis. We have undertaken this study to conrm such an association and to predict which cases of PLE are likely to have hypothyroidism and autoimmune thyroiditis. METHODS This was a cross-sectional study with comparative group with 75 PLE cases and 75 controls. Thyroid function test (TFT) was done for all subjects and, if found abnormal, anti-thyroid peroxidase (TPO) antibodies were tested. The studied parameters were compared using Pearson's chi-squared test for signicance. RESULTS The male to female ratio was 1:2.1. Hypothyroidism and autoimmune thyroiditis were signicantly present in PLE cases. PLE lesions with papular morphology, persistent and recurrent PLE, positive family history and associated other autoimmune diseases were signicantly associated with autoimmune thyroiditis. CONCLUSION PLE is signicantly associated with hypothyroidism and autoimmune thyroiditis. Hence we suggest screening of PLE patients for hypothyroidism and, if required, for autoimmune thyroiditis for early diagnosis and treatment.