Is Frictional Lichenoid Dermatitis a Minor Variant of Atopic Dermatitis or a Photodermatosis.

Context: Frictional lichenoid dermatitis. Background: Frictional lichenoid dermatitis (FLE) is an entity that is probably under diagnosed and has been variably associated with either friction and/or atopy with a distinctive seasonal variation. Aims and Objectives: To study correlation of FLE with UV index and to assess its association with atopic dermatitis. Materials and Methods: A cross sectional analysis of children with FLE was done, over a period of 6 years in two tertiary hospitals. A detailed history and examination was done to assess the features of atopic dermatitis. The number of cases seen per month was compared with the mean monthly UV index. Two‑tailed significance tests using Pearson's coefficient of correlation and T‑test were used to interpret the data. (P < 0.05). Results: One hundred seventy‑four patients were studied using the UKC criterion 17.2% of the patients had AD while xerosis (40.3%) was the predominant cutaneous finding. The number of patients seen in summer was more than in winter (P < 0.05) but there was no statistical difference between the cases in winter and spring. There was a significant correlation of the number of cases per month with UV index (P = 0.019). Almost 42% of patients gave a history of recurrence. Conclusions: FLE is probably not associated with atopic dermatitis and is likely to be related to the ambient UV index though a larger cohort with meticulous follow up may be needed to draw a final conclusion. Statistical Analysis Used: The Pearson's coefficient of correlation was used for comparing the cases per month with the UV index. The tests of hypothesis used included the paired T‑tests. F‑test of variance, Welch test, Wilcoxon rank sum test and the Kolmogorov‑Smirnov Test. P < 0.05 was considered significant. [ABSTRACT FROM AUTHOR]