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 conrm 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 signicance.
RESULTS The male to female ratio was 1:2.1. Hypothyroidism and autoimmune thyroiditis were signicantly present in PLE
cases. PLE lesions with papular morphology, persistent and recurrent PLE, positive family history and associated other
autoimmune diseases were signicantly associated with autoimmune thyroiditis.
CONCLUSION PLE is signicantly 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.