Track

Case Reports

Abstract

Iododerma is a rare halogenoderma resulting from exposure to products containing iodine. It is challenging to diagnose due to variable clinical and histopathological presentations. Here, we report a case of iododerma in a 40-year old hospitalized male patient who received intravenous iodinated contrast for computed tomography imaging for a subarachnoid hemorrhage. Three days later, dermatology was consulted for rapidly progressive large retiform purpuric plaques on the patient’s bilateral upper extremities, hemorrhagic bullae on the dorsal right hand, and shiny red to purple papules on the scalp and face. Dermatopathology demonstrated ruptured acute folliculitis with a neutrophilic infiltrate, fibrinoid necrosis of vessels with rare fibrin thrombi, and haloed cryptococcal-like structures filling the upper dermis. No organisms including Cryptococcus were seen on periodic acid-Schiff, Grocott’s methenamine silver, Alcian blue, Fontana-Masson, and pancytokeratin special stains. CD163, CD68, CD15, and myeloperoxidase stained positive. CD3, CD20, CD43, CD33, CD34, and lysozyme stained negative. Direct immunofluorescence showed variable perivascular deposition of IgG, IgM, IgA, C3, and fibrinogen. Infectious work-up including tissue cultures for bacterial, mycobacterial, and fungal organisms was negative. Vasculitis work-up was notable only for positive perinuclear anti-neutrophil cytoplasmic antibodies. Antinuclear antibody, myeloperoxidase/proteinase 3 antibodies, cryoglobulins, complement levels, and antiphospholipid antibody panel were normal. These findings in combination with a serum iodine level of greater than 100,000 µg/L (normal: 40-92 µg/L) cinched the diagnosis of iododerma. We present this case to highlight the unique histopathological features of this condition and the importance of clinicopathological correlation.