Multiple pulmonary cavitary nodules with pyoderma gangrenosum in patient with rheumatoid arthritis

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic disorder of skin. Its pulmonary manifestations are uncommon and only less than forty cases have been reported in the literature previously. PG is associated with variable systemic diseases, most commonly inflammatory bowel disease and hematologic malignancies. It reported rarely in rheumatoid arthritis (RA). We report a case of PG lung involvement in patient with RA associated interstitial lung disease. A 66-year-old woman presented with productive cough and recurrent ulcerative lesion on her left ankle. She had a 15-year history of RA associated interstitial lung disease and treated with methotrexate, sulfasalazine, hydroxychloroquine and methylprednisolone. On physical examination, there were a few tender, erythematous subcutaneous nodules ranging from 1 to 3 cm in diameter on her left thigh and left elbow. Anti-neutrophil cytoplasmic antibodies (ANCAs) are negative. Her chest CT scan demonstrated multifocal cavitary consolidations on the background of reticular opacity and honeycombing. Punch biopsy of erythematous nodule on thigh showed neutrophilic abscess with necrotic debris. The skin and lung lesions were rapidly improved with
0.5 mg/kg/day of prednisolone.