BACKGROUND Chronic Granulomatous Disease (CGD) is a rare immunodeficiency disease caused by a genetic defect in the NADPH (nicotinamide adenine dinucleotide phosphate) oxidase enzyme, resulting in increased susceptibility to bacterial and fungal infections. The inheritance can be X-linked or autosomal recessive. Patients usually present with repeated infections early in life. We present an unusual case of a 23-year-old patient diagnosed with CGD. CASE REPORT A 23-year-old white woman with no previous history of recurrent infections presented with complaints of fever, shortness of breath, and diffuse myalgia. She had been treated twice for similar complaints recently, but without resolution. She was febrile, tachypneic, tachycardic, and hypoxic at presentation. Physical examination revealed diffuse inspiratory rales. Laboratory results showed leukocytosis. Her initial chest X-ray and CT chest showed reticular nodular interstitial lung disease pattern. Despite being on broad-spectrum antibiotics for 5 days, she continued to require supplemental oxygen and continued to be tachypneic, with minimal activity. Initial diagnostic tests, including bronchoscopy with biopsy and lavage, did not reveal a diagnosis. She then underwent a video-assisted thoracoscopic surgery (VATS) lung biopsy. The biopsy slides showed suppurative granulomatous inflammation affecting greater than 50% of the parenchymal lung surface. Fungal hyphae consistent with Aspergillus were present in those granulomas. A diagnosis of CGD was made and she was started on Voriconazole. She improved with treatment. Her neutrophil burst test showed negative burst on stimulation, indicating phagocytic dysfunction consistent with CGD. Autosomal recessive CGD was confirmed by genetic testing. CONCLUSIONS CGD can present in adulthood without any previous symptoms and signs. Clinicians should consider this disease in patients presenting with recurrent or non-resolving infections. Timely treatment and prophylaxis has been shown to reduce serious infections as well as mortality in these patients.