Introduction: Severe hypercortisolism is associated with profound impairment of both innate and adaptive immune responses, predisposing affected individuals to opportunistic infections. Excess glucocorticoids alter leukocyte trafficking, suppress pro-inflammatory cytokine production, and impair cellular immunity, increasing susceptibility to bacterial, viral, and fungal pathogens. In some cases, severe infections may precede the diagnosis of Cushing syndrome and represent the initial clinical manifestation. Early recognition is important as untreated hypercortisolism can lead to substantial morbidity and mortality. Case: A young adolescent male presented with progressive facial fullness and facial hyperpigmentation for 4 months, followed by 1 month of intermittent fever, cough, lower limb weakness, and hallucinations. On examination, he was tachypneic with cushingoid features including moon facies, pigmented acne over the face and chest, and nail bed hyperpigmentation. He was hypertensive and had severe hypokalemia with lymphopenia. Radiological imaging demonstrated multiple cavitary lung lesions and intracranial tuberculomas. Bronchoalveolar lavage identified multiple opportunistic pathogens, including Pneumocystis jirovecii, Aspergillus fumigatus, and Haemophilus influenzae, while cerebrospinal fluid testing was positive for cytomegalovirus. Given the unusual combination of infections, an underlying immunocompromised state was suspected. Endocrine evaluation revealed markedly elevated serum cortisol, with loss of diurnal rhythm and elevated adrenocorticotropic hormone (ACTH). Twenty-four-hour urinary cortisol was significantly increased, confirming severe ACTHdependent Cushing syndrome. Magnetic resonance imaging of the pituitary gland and computed tomography imaging of the thorax, abdomen, and pelvis did not identify the source of ACTH secretion. Conclusion This case highlights that overwhelming opportunistic infections may be the first manifestation of severe Cushing syndrome in children. Excess cortisol disrupts host defenses by impairing neutrophil chemotaxis and macrophage phagocytosis, suppressing T-cell-mediated immunity, and reducing cytokine signaling necessary for pathogen clearance. These mechanisms contribute to susceptibility to simultaneous bacterial, fungal, and viral infections. Clinicians should therefore consider underlying hypercortisolism in patients presenting with multiple or unusual opportunistic infections to enable earlier diagnosis and appropriate multidisciplinary management.
Cushing Syndrome ; Opportunistic Infections