A previously healthy 25-year-old music teacher develops fever and a rash over her face and chest. The rash is itchy and, on examination, involves multiple papules and vesicles in varying stages of development. One week later, she complains of cough and is found to have an infiltrate on x-ray. Which of the following is the most likely etiology of the infection?A) Streptococcus pneumoniae
Varicella pneumonia develops in about 20% of adults with chickenpox. It occurs 3 to 7 days after the onset of the rash. The hallmarks of the chickenpox rash are papules, vesicles, and scabs in various stages of development. Fever, malaise, and itching are usually part of the clinical picture. The differential can include some coxsackievirus and echovirus infections, which might present with pneumonia and vesicular rash. Rickettsial pox, a rickettsial infection, has also been mistaken for chickenpox. Although the pneumococcus, Mycoplasma, and Chlamydia are common causes of community-acquired pneumonia in young adults, they would not account for the preceding vesicular rash. Histoplasmosis can cause acute pneumonitis after a large exposure but would not account for the rash.