Differential Diagnosis for Diplopia with Tick Bite
- Single most likely diagnosis
- Tick paralysis: This condition is caused by a neurotoxin in the saliva of certain ticks, which can lead to ascending paralysis and cranial nerve dysfunction, including diplopia (double vision). The temporal association with a tick bite makes this a highly plausible diagnosis.
- Other Likely diagnoses
- Lyme disease: Caused by the bacterium Borrelia burgdorferi, transmitted by the bite of infected black-legged ticks. Neurological manifestations, including cranial neuritis which could lead to diplopia, can occur in the early disseminated stage of the disease.
- Southern tick-associated rash illness (STARI): Although primarily known for its rash, there have been reports of neurological symptoms, and while less common, it could potentially lead to conditions causing diplopia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rocky Mountain spotted fever (RMSF): A severe and sometimes fatal disease caused by Rickettsia rickettsii, transmitted by the bite of infected ticks. Neurological symptoms, including those that could lead to diplopia, can occur, and prompt treatment is essential.
- Tularemia: Caused by Francisella tularensis, this infection can be transmitted by tick bites and can lead to severe illness, including ocular manifestations that might result in diplopia.
- Rare diagnoses
- Babesiosis: A disease caused by Babesia, a parasite transmitted by tick bites. While primarily known for causing hemolytic anemia, severe cases can lead to neurological symptoms, potentially including diplopia, though this would be uncommon.
- Ehrlichiosis: Caused by Ehrlichia species, these are tick-borne bacterial infections that can lead to severe illness, including neurological manifestations in rare cases, which might include diplopia.
- Anaplasmosis: Similar to Ehrlichiosis, Anaplasma phagocytophilum infection can cause a severe disease with potential neurological involvement, though diplopia would be an unusual presentation.