A 17-year-old male presents with a history of increasing dyspnea, dry cough, and low-grade fevers. Coalescing erythematous macular lesions are evident on his hands, and hemorrhagic erosions are present on his lips. Lung auscultation reveals crackles bilaterally and a chest x-ray demonstrates a reticulonodular pattern without consolidation. What is the most likely diagnosis? Image credit: @mblaze.