Case Presentation: A 37-year-old Hispanic female with no medical history presented to the hospital with bilateral lower extremity edema of 3-week duration. Concurrently, she also experienced dysphagia to solids associated with 30-lb weight loss and low-grade fever. Initial examination was significant for bilateral erythematous rash of lower extremities with 3+ pitting edema that extended from the knees to the ankles. Upon palpation, multiple 2-3 cm tender nodules with central pallor and surrounding erythema were present on the medial aspects of her legs consistent with a clinical diagnosis of erythema nodosum. Further examination revealed ulcerations around her fingernails.Labs revealed a microcytic anemia and hyponatremia. Further testing found elevated creatine kinase (4695 IU/L) and elevation of liver enzymes. Her urinalysis showed microscopic hematuria, hyaline casts, RBC cellular casts and 720 mg protein/24 hr. Autoimmune workup was positive for ANA, anti-Ro, and anti-U1RNP. Her C3, C4 and C1q were low. Her anti-dsDNA, anti-Histone, anti-Smith, anti-Jo, and anti-La were negative. CXR was unremarkable and TB-quantiferon was negative.
Given these labs along with proteinuria >500 mg and microscopic hematuria, a kidney biopsy was performed showing diffuse mesangial expansion on light microsopy. Immunofluorescence showed granular staining on mesangial areas positive for IgG, IgM, IgA, C3, and Kappa/Lambda consistent with class II lupus nephritis. Due to severe dysphagia, an esophageal manometry was recommended, showing discordant peristalsis. Subsequently, diagnosis of SLE was made. Management with corticosteroids, hydroxychloroquine, mycophenolate mofetil, and domperidone were initiated with significant improvement at three weeks.

Discussion: Infections are the most common cause of EN. Drugs, IBD, and malignancies are the other common precipitants. EN presents as 2-5 cm tender, non-ulcerated sub-acute nodules associated with fever and systemic symptoms. Our patient presented with bilateral EN with systemic symptoms without infection or sarcoidosis, prompting further evaluation into inflammatory and rheumatologic processes. Kidney biopsy revealed class II lupus nephritis that along with positive ANA was diagnostic for SLE according to Systemic Lupus International Collaborating Criteria (SLICC). Esophageal manometry showed GI involvement, secondary to underlying myopathy. Given heterogeneity of disease, SLE treatment is guided by the predominant manifestations. Due to severity of disease, immunosuppressive therapy and steroids were started to relieve constitutional and cutaneous manifestations with resolution of symptoms.

Conclusions: SLE is a systemic disease, which involves multiple organs including the skin, kidneys, and gastrointestinal system. EN is commonly secondary to infection, drugs or IBD; however, it can be an uncommon manifestation of SLE.