A clinicopathological study of polymorphous light eruption

Background: Polymorphous light eruption (PLE) is the most common idiopathic photodermatoses, with a wide range of clinical presentations that tends to mimic a number of dermatoses. Objective: The aim was to study the clinicopathological profile in patients diagnosed with PLE. Materials and Methods: This was a cross-sectional, descriptive study of seventy clinically diagnosed cases of PLE over a period of 1 year, wherein following patient enrolment, they underwent a thorough clinical evaluation, followed by a skin biopsy that was studied categorically. Results: A male preponderance (62.8%) was observed. Majority of patients were in the 21-30 years' age group (28.6%). Pruritus was witnessed in 98.5% of patients. The most common morphological type encountered was plaque PLE (35.7%), followed by lichen nitidus type (11.4%). Commonest site of involvement was sides and back of neck (75.7%), followed by dorsolateral aspect of both arms (31.4%). Hyperkeratosis was identified in 82.8%, spongiosis in 87.1%, liquefactive degeneration of basal cell layer in 82.8%, atrophy in 24.2%, and moderate-to-severe lymphocytic dermal infiltrates in 90% of our cohorts. Conclusion: PLE is a disorder with diverse clinical presentations, manifesting usually in the third decade of life that closely mimics a variety of other cutaneous disorders. Histological examination with certain specific criteria enables the clinician to arrive at a concrete conclusion in those cases where clinical findings alone pose diagnostic difficulties.