Hemophagocytic Lymphohistiocytosis Triggered by Acute Interstitial Pneumonitis in a Young Woman With Rheumatoid Arthritis.

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon but potentially life-threatening condition where the body's immune system becomes overactive, causing widespread inflammation and organ damage. In this report, we present the case of a 21-year-old woman with a history of rheumatoid arthritis who developed secondary HLH, triggered by acute interstitial pneumonitis (AIP). This case sheds light on the importance of early recognition and intervention in managing this rare condition. It emphasizes the need to consider HLH in patients presenting with unexplained systemic inflammation similar to this case, particularly when triggered by AIP, as evidenced by the respiratory involvement in this case.