Abstract
BACKGROUND Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection that commonly occurs in immunocompromised patients, especially those with HIV. Early diagnosis and prompt treatment are important because PJP is a potentially life-threatening infection. However, the diagnosis of PJP in the early stage can be challenging due to various factors. Furthermore, the early presentation of PJP, which includes normal chest radiograph and examination findings along with the subacute presentation of PJP in patients with HIV, makes an early diagnosis of the disease even more challenging for doctors. CASE REPORT In this case report, we present the case of a 39-year-old man who had normal chest X-ray findings during the initial stage of his presentation. Coupled with non-disclosure of HIV status, these led to a delay in PJP diagnosis. The diagnosis of PJP with underlying HIV was later supported by the patient's clinical features, initial blood investigations, and presence of high-risk sexual activity. The diagnosis was confirmed when the PJP polymerase chain reaction test from the respiratory sample was positive. He was successfully treated with oral trimethoprim-sulfamethoxazole. However, he subsequently developed rare adverse effects of drug-induced immune hemolytic anemia, which was diagnosed based on the presence of hemolytic anemia and recent exposure to a new drug. Trimethoprim-sulfamethoxazole was promptly discontinued, which resulted in symptom improvement. CONCLUSIONS This case report aims to create awareness among primary care doctors to be vigilant of the PJP diagnosis and its nonspecific presentations as well as to the rare adverse effects of medications to treat PJP.