Differential Diagnosis for 2 yo Male with Tick Bite and Positive Exposure to Lyme
- Single most likely diagnosis
- Lyme disease: This is the most likely diagnosis given the patient's age, tick bite, and positive exposure to Lyme. Lyme disease is a common tick-borne illness caused by the bacterium Borrelia burgdorferi, and early stages can present with symptoms such as fever, headache, and a characteristic "bull's-eye" rash.
- Other Likely diagnoses
- Southern tick-associated rash illness (STARI): This condition presents with a similar rash to Lyme disease but is caused by a different tick-borne illness. It's less common than Lyme but still a consideration in areas where the Lone Star tick is prevalent.
- Ehrlichiosis: This is another tick-borne illness that can present with fever, headache, and rash, although the rash is less common in Ehrlichiosis than in Lyme disease.
- Babesiosis: A parasitic disease transmitted by ticks, babesiosis can cause symptoms such as fever, fatigue, and anemia, although it's less likely to cause a rash.
- Do Not Miss diagnoses
- Rocky Mountain spotted fever (RMSF): Although less common, RMSF is a serious and potentially deadly tick-borne illness that requires prompt treatment. It presents with fever, headache, and a characteristic rash that can appear a few days after the onset of fever.
- Tick-borne relapsing fever (TBRF): This condition, caused by various Borrelia species, can lead to recurrent episodes of fever and is more common in certain geographic areas. It's crucial to consider TBRF due to its potential for severe outcomes if not treated.
- Rare diagnoses
- Anaplasmosis: Another tick-borne disease that can cause fever, headache, and muscle pain, anaplasmosis is less common and might not always be considered initially but should be kept in mind, especially in endemic areas.
- Powassan virus disease: A rare but potentially severe tick-borne viral disease that can cause encephalitis or meningitis, making it a critical diagnosis not to miss, despite its low incidence.
- Tularemia: Caused by the bacterium Francisella tularensis, tularemia can be transmitted by ticks and presents with symptoms such as fever, skin ulcers, and swollen lymph nodes. It's rare but can be severe and requires prompt antibiotic treatment.