A Case of Glucocorticoid Hypersensitivity Syndrome Associated With Underlying Rubella Virus Infection

OBJECTIVE: The objective of this article is to report a rare case of glucocorticoid hypersensitivity syndrome, which may be associated with an underlying rubella virus infection. CASE REPORT: A 29-year-old man showed progressive weight gain for 16 months accompanied by a moon face, enlarged dorsocervical fat pad, central obesity, and purple striae. His cortisol circadian rhythm was normal, and plasma cortisol levels at 8:00 AM fluctuated between 3.2 and 9.54 μg/dL (reference range, 4.3-22.4 μg/dL). A dexamethasone suppression test with a very low dose (0.25 mg) of dexamethasone showed a marked decrease in plasma cortisol level to 0 μg/dL. Adrenal computed tomography and pituitary magnetic resonance imaging findings were normal. The Z-score of the bone density in the lumbar spine was −4.2. The IgM antibody for the rubella virus was positive. His erythrocyte sedimentation rate was 24 mm/hour (reference range, <15 mm/hour), and the C-reactive protein level was 9.22 mg/L (reference range, <5 mg/L). After 3 months, his symptoms resolved spontaneously. The erythrocyte sedimentation rate and C-reactive protein level returned to normal. The IgM antibody for the rubella virus turned negative, whereas the IgG antibody for the rubella virus was positive. DISCUSSION: According to the paradox between clinical manifestations and laboratory tests exogenous Cushing syndrome, cyclical Cushing syndrome, and glucocorticoid hypersensitivity syndrome all should be considered in the diagnosis. Detailed medical history inquiry, complete endocrine hormone testing, and continuous follow-up are all critical for diagnosis. CONCLUSION: Consequently, the patient was diagnosed with glucocorticoid hypersensitivity syndrome. This case illustrates the need to consider the possibility of glucocorticoid hypersensitivity syndrome in a patient who has the manifestations of Cushing syndrome but paradoxical hypocortisolemia, especially after rubella virus infection.