Direct immunofluorescence and histopathology in chronic discoid lupus erythematosus

Background Lesions of chronic discoid lupus erythematosus (DLE) are characterized by sharply demarcated, scaly, infiltrated and later atrophic red discoid plaques. They have pathognomonic histological features, helping in confirmation of the diagnosis. Since the introduction of direct immunofluorescence, the lupus band test has become an important tool for the diagnosis of cutaneous lupus erythematosus. Objective To elaborate the specific histopathological features and direct immunofluorescence findings in the lesions of chronic discoid lupus erythematosus. Patients and methods Patients of any age and either sex presenting with clinically suggestive lesions of discoid lupus erythematosus, attending the outpatient dermatology department of Mayo Hospital were enrolled. The biopsy specimens of the lesional skin were bisected and subjected to histopathology and direct immunofluorescence. Results Out of 29 patients, the diagnostic histopathological features were found in 23 (79.9%) patients, in 5 (16%) the changes were suggestive. We could not reach to a diagnosis in one patient. Diagnostic lupus band was found in 20 (68.5%), while fluorescence at dermoepidermal junction was suggestive of lupus band in 3 (11%). No fluorescence was observed in 6 (20.5%). A combination of the two techniques gave better results 85%. Conclusion Direct immunofluorescence is a useful technique in the diagnosis of discoid lupus erythematosus; however, it should be used in conjunction with haematoxylin and eosin-stained sections