Differential Diagnosis
- Single most likely diagnosis
- Lyme meningitis: Given the patient's symptoms of fever, headache, neck pain, photophobia, and mild nuchal rigidity, along with the presence of a diffuse maculopapular rash and generalized adenopathy, Lyme meningitis is a strong consideration. The patient lives in Boston, Massachusetts, an area endemic for Lyme disease, which further supports this diagnosis.
- Other Likely diagnoses
- Viral meningitis: The patient's symptoms of fever, headache, and neck pain, along with the cerebrospinal fluid (CSF) results showing a lymphocytic predominance, are consistent with viral meningitis. However, the negative PCR testing for enterovirus and herpes simplex virus reduces the likelihood of this diagnosis.
- Infectious mononucleosis: The patient's symptoms of fever, headache, and generalized adenopathy, along with the presence of a diffuse maculopapular rash, are consistent with infectious mononucleosis. However, the CSF results are not typical for this diagnosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Bacterial meningitis: Although the CSF results show a lymphocytic predominance, bacterial meningitis can present with similar symptoms and must be considered due to its high mortality rate if left untreated. The patient's fever, headache, and neck pain, along with the presence of photophobia and mild nuchal rigidity, warrant careful consideration of this diagnosis.
- Tuberculous meningitis: This diagnosis is less likely given the patient's presentation and the lack of risk factors, but it is a potentially deadly condition that must be considered, especially if the patient has been exposed to tuberculosis or has a weakened immune system.
- Rare diagnoses
- Syphilitic meningitis: Although rare, syphilitic meningitis can present with similar symptoms, including fever, headache, and neck pain, along with a rash and generalized adenopathy. The patient's sexual activity increases the likelihood of this diagnosis, but it is still a rare consideration.
- Leptospirosis: This diagnosis is rare in the United States, but it can present with similar symptoms, including fever, headache, and neck pain, along with a rash and generalized adenopathy. The patient's occupation as a barista and lack of exposure to contaminated water reduce the likelihood of this diagnosis.