Erythema nodosum — A diversity of diagnostic potential!

Abstract

Erythema nodosum results from an inflammatory reaction in the subcutaneous fat and is characterized by acute onset of painful and ill-defined erythematous nodules that can best be seen than felt. Is associated with many differential diagnoses such as infections, drugs, sarcoidosis, inflammatory bowel disease and cancer. What was the etiology present in this case. The authors describe a case of a woman of 72 years old, living in rural areas. Personal history of hypertension and dyslipidemia was medicated with perindopril, indapamide and statin. Admitted by symptoms such as anorexia, weight loss (not quantified), fever and neck pain with 8 days of evolution, associated with the onset of painful erythematous nodules around the abdomen, upper and lower limbs two days before. The patient denied sore throat or flu-like illness in the previous weeks, as well as foreign travel, other new medications or relatives with the same symptoms. On physical examination no changes except painful erythematous nodules in the abdomen, back, upper and lower limbs, in different stages of evolution. Analytically had macrocytic normochromic anemia (9.6 g/dL), leukopenia (3300/μL), increased erythrocyte sedimentation rate (112 mm/h) and monoclonal peak range on the electrophoresis (IgM/kappa). The remaining analytical study performed, including immune, angiotensin converting enzyme, TASO (streptococcal serology) and bacterial, viral or fungal infection, was negative, as all microbiological research. All body CT-scan and digestive endoscopies without any evidence of pathology. Bone marrow biopsy was performed with the diagnostic of myelodysplastic syndrome (refractory anemia with excess blasts (RAEB-1)), checking the presence of 7% blasts and complex karyotypes with multiple chromosomal abnormalities, including del 5q - 16%. With this result it was decided by treatment with Azacitidine. The cause of erythema nodosum is a diagnostic challenge on the Internal Medicine because of the diversity of pathologies associated with it (from a pharyngitis to a neoplasm). With this case report, the authors intend to demonstrate that the presence of myelodysplastic syndrome can also manifest as erythema nodosum, which must be part of the differential diagnosis of this panniculitis.