Diagnostic significance of colloid body deposition in direct immunofluorescence

Background: Colloid bodies (CB) in direct immunofluorescence (DIF) studies are usually found in interface dermatitis. Furthermore, CB can be found in various skin diseases and even in normal skin. Aim: To evaluate the diagnostic value of CB deposits in DIF studies. Methods: From 1996-2007, data from 502 patients where DIF studies showed immunoreactants at CB were enrolled. The definite diagnoses of these patients were based on clinical, histopathological and immunofluorescent findings. The results of DIF studies were analyzed. Results: Immunoreactants at CB were detected in 44.4%, 43.8%, 4.2%, 3.8%, and 2.2% of interface dermatitis, vasculitis, autoimmune vesiculobullous disease, panniculitis, and scleroderma/morphea, respectively. The most common immunoreactant deposit of all diseases was Immunoglobulin M (IgM). Brighter intensity and higher quantity of CB was detected frequently in the group with interface dermatitis. Conclusions: Immunoreactant deposits at CB alone can be found in various diseases but a strong intensity and high quantity favor the diagnosis of interface dermatitis. CB plus dermoepidermal junction (DEJ) deposits are more common in interface dermatitis than any other disease. Between lichen planus (LP) and discoid lupus erythematosus (DLE), CB alone is more common in LP; whereas, CB plus DEJ and superficial blood vessel (SBV) is more common in DLE. The most common pattern in both diseases is CB plus DEJ. The quantity and intensity of CB in LP is higher than in DLE.