Although sarcoidosis is associated with common variable immunodeficiency (CVID), this diagnosis is difficult to make in CVID patients. Diagnosing sarcoidosis is dependent on a combination of clinical, radiologic, and histologic findings. The hallmark of sarcoidosis is the presence of noncaseating granulomas. However, granulomas are also found in CVID. We describe a patient with CVID who developed erythema nodosum (EN) and was ultimately diagnosed with sarcoidosis.

A 42-year-old woman with a 25-year history of CVID, well-controlled by monthly intravenous immunoglobulin therapy, had a marked deterioration in her clinical status. She developed worsening dyspnea, fatigue, and weight loss. Pulmonary function tests showed both restrictive and obstructive patterns. A CT of the chest revealed mediastinal adenopathy and bronchiectasis. A CT of the abdomen demonstrated a massively enlarged spleen. She developed refractory anemia and thrombocytopenia secondary to hypersplenism and a splenectomy was performed. The pathology revealed a 1.9 kg spleen with caseating and noncaseating granulomas. There was no evidence of infection or lymphoproliferative disease. Nine months later the patient developed painful nodular lesions on the extensor surface of her forearms and shins. Biopsy revealed septal panniculitis consistent with EN. Given the patient's pulmonary symptoms, chest radiographs, granulomas, and EN, the diagnosis of sarcoidosis was made.

It is difficult to diagnose sarcoidosis in a patient with CVID. Sarcoidosis should be included in the differential diagnosis in CVID patients with worsening pulmonary symptoms, splenomegaly, and EN.