Palisaded neutrophilic and granulomatous dermatitis following a long-standing monoclonal gammopathy: A case report

Background: Palisaded neutrophilic granulomatous dermatitis is a rare inflammatory dermatosis with possible underlying systemic conditions including rheumatoid arthritis, autoimmune connective tissue disease, and malignancies. Case Summary: We report a case of an 84-year-old man presenting with a 3-week eruption of asymptomatic annular plaques on his neck, which progressed to involve his back and legs. Skin biopsies confirmed a diagnosis of palisaded neutrophilic granulomatous dermatitis, and he was treated with prednisone. Full workup related to potential underlying causes of palisaded neutrophilic granulomatous dermatitis was completed. Conclusion: Palisaded neutrophilic granulomatous dermatitis may precede the onset of underlying systemic conditions or occur concomitantly. Following the diagnosis, clinicians should perform a comprehensive focused history, physical examination, and laboratory investigation related to the associated underlying diseases.