Differential Diagnosis for 35yo M with Swollen Lymph Nodes and Deer Tick Bite
- Single most likely diagnosis
- Lyme disease: The patient's symptoms, including swollen lymph nodes, erythema, joint pain, and fatigue, are consistent with early disseminated Lyme disease, which can occur after a deer tick bite. The patient's occupation and frequent exposure to tick bites increase his risk.
- Other Likely diagnoses
- Southern tick-associated rash illness (STARI): Although less common, STARI can cause similar symptoms, including a rash and systemic symptoms, after a tick bite.
- Tick-borne relapsing fever: This condition, caused by Borrelia species, can lead to fever, headache, and muscle pain, which may be accompanied by lymphadenopathy.
- Ehrlichiosis or Anaplasmosis: These tick-borne illnesses can cause fever, headache, fatigue, and lymphadenopathy, although they are less likely given the patient's specific symptoms.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rocky Mountain spotted fever (RMSF): Although rare in this region, RMSF is a life-threatening condition that requires prompt treatment. The patient's symptoms, including fever, headache, and rash, could be consistent with RMSF.
- Tularemia: This bacterial infection, transmitted by ticks, can cause severe illness, including pneumonia, and requires prompt antibiotic treatment.
- Rare diagnoses
- Babesiosis: A parasitic infection transmitted by ticks, babesiosis can cause hemolytic anemia, fever, and fatigue, although it is relatively rare.
- Powassan virus disease: A rare tick-borne viral illness that can cause encephalitis or meningitis, although it is unlikely given the patient's symptoms.