title: Thyroid function tests in cases of polymorphic light eruption: A case-control study.
abstract: BACKGROUND
  Polymorphic light eruption (PLE) has been found to be associated with thyroid function abnormalities.
  
  
  OBJECTIVE
  To study clinicoepidemiological features of PLE and to study and compare thyroid function tests (TFTs) in cases of PLE.
  
  
  METHODS
  The study included 100 cases of PLE and age- and sex-matched controls attending a skin outpatient department. The clinical and epidemiological features were recorded. Both cases and controls were tested for thyroid-stimulating hormone (TSH). In case of abnormality in TSH, triiodothyronine (T3) and tetraiodothyronine (T4) levels were estimated.
  
  
  RESULTS
  TFT was abnormal in 25 cases and 7 controls. TSH was elevated in 24 cases and 6 controls and decreased in 1 case and 1 control. T3 and T4 were decreased in 18 cases and 6 controls and elevated in 1 each in case and control. Hypothyroidism was significantly high among cases than controls.
  
  
  CONCLUSIONS
  TFT abnormality was significantly higher among cases than controls. Hypothyroidism has a significant association with PLE. Genetic basis or immune dysfunction may be the cause of both the diseases. PLE may be considered as a clinical presentation of thyroid function disorder and vice versa.
  
  
  CONCLUSIONS
  Cases of PLE should be examined clinically for thyroid disorder and also tested for TSH or TFT to find any association and prevent serious consequences.
authors.affiliation: Department of Dermatology and Venereology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Lata
authors.initials: L
authors.lastname: Sharma
authors.affiliation: Department of Dermatology and Venereology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Sachin
authors.initials: S
authors.lastname: Lamba
authors.affiliation: Department of Endocrinology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Sk
authors.initials: S
authors.lastname: Singh
keywords: Clinical and epidemiological; polymorphic light eruption; tetraiodothyronine; thyroid function tests; thyroid-stimulating hormone; triiodothyronine