Abstract Background Pneumocystis jirovecii pneumonia (PJP) is a life-threatening opportunistic infection frequently associated with human immunodeficiency virus (HIV). We report an atypical presentation of this disease, mimicking interstitial lung disease (ILD). Case Presentation We report the case of a 26-year-old previously healthy man presenting with fever, cough and shortness of breath. Initial improvement under antibiotics was followed by persistent dyspnoea. Imaging revealed diffuse ILD with ground-glass opacities and subpleural sparing. Bronchoalveolar lavage (BAL) showed lymphocytic predominance. An extensive immunological workup, including antinuclear antibodies, rheumatoid factor, anti–cyclic citrullinated peptide antibodies, antineutrophil cytoplasmic antibodies, extractable nuclear antigen antibodies and myositis-specific antibodies, was negative. HIV serology was requested due to persistent diarrhoea, and its positive result proved to be the key diagnostic clue that prompted evaluation for opportunistic infections, ultimately leading to the confirmation of PJP. Treatment with trimethoprim-sulphamethoxazole led to clinical improvement. Conclusion This case highlights that pneumocystis pneumonia may present atypically, simulating ILD. HIV screening should be considered in the aetiological workup of unexplained ILD to enable early diagnosis and appropriate management.
Mtar et al. (Thu,) studied this question.