Iatrogenic Cushing’s Syndrome with Secondary Adrenal Suppression Misdiagnosed as Protease Inhibitor-Induced Lipodystrophy in an HIV Positive Patient: Case Report

Background: Ritonavir is a commonly prescribed protease inhibitor (PI) which is used in low doses to boost levels of other protease inhibitors pharmacokinetically. It is a potent inhibitor of hepatic cytochrome P450 3A4 (CYP3A4) isoenzyme and reduces the metabolism of systemic steroids leading to clinical Cushing's syndrome and secondary adrenal insufficiency. Despite occasional reports of Cushing's syndrome occurring with the use of injectable triamcinolone, even in the absence of CYP3A4 inhibition, it is unclear if caution should be exercised when considering local steroid injections in the setting of ritonavir therapy. We herein report the case of an iatrogenic steroid induced Cushing's syndrome due to triamcinolone-ritonavir interaction misdiagnosed as PI induced lipodystrophy. Case Presentation: We present the case of a 47-year-old HIV positive African male patient, who was switched from Tenofovir/ Lamivudine/ Efavirenz combination therapy to Abacavir/ Lamivudine/ Atazanavir/ Ritonavir due to virologic failure and had been on this new regimen for 1 year. He had been on over-the-counter intramuscular triamcinolone for 3 months, for knee pain and presented with a 2-month history of weight gain, swollen face and distended abdomen. Clinical examination revealed a moon face, dorsocervical hump, central obesity, fair skin, and pitting edema. He was initially thought to have PI induced lipodystrophy but after thorough examination and laboratory investigations, a diagnosis of iatrogenic Cushing syndrome with adrenal suppression was made and he was managed with hydrocortisone replacement therapy with marked regression of symptoms thereafter. Conclusion: Cushing's syndrome should be considered as an important differential in HIV positive patients on PI who develop abnormal fat deposition, especially in the context of steroid use. A high index of suspicion is required for early diagnosis and management. Whenever possible, the use of glucocorticoid therapy through any route should be avoided in patients on ritonavir-boosted protease inhibitor therapy.