Differential Diagnosis for Neck Stiffness + Petechial Rash
- Single most likely diagnosis
- Meningococcal meningitis: This condition is characterized by the sudden onset of neck stiffness, fever, and a petechial rash. The rash is typically non-blanching and can progress to purpura. Meningococcal meningitis is a medical emergency that requires prompt treatment.
- Other Likely diagnoses
- Viral meningitis: Although less common to present with a petechial rash, some viral meningitis cases can have a rash, and neck stiffness is a hallmark symptom.
- Bacterial endocarditis: This condition can cause a petechial rash and may lead to neurological symptoms, including neck stiffness, due to embolic phenomena.
- Rocky Mountain spotted fever: This tick-borne illness can cause a petechial rash and may involve the central nervous system, leading to symptoms like neck stiffness.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subarachnoid hemorrhage: Although not typically associated with a petechial rash, a severe headache and neck stiffness could be indicative of a subarachnoid hemorrhage. The presence of a rash might be incidental or related to another condition, but the severity of the headache and neck stiffness warrants consideration of this diagnosis.
- Meningitis due to other bacteria (e.g., Streptococcus pneumoniae, Haemophilus influenzae): These infections can present similarly to meningococcal meningitis and are medical emergencies.
- Rare diagnoses
- Thrombotic thrombocytopenic purpura (TTP): A rare blood disorder that can cause a petechial rash and neurological symptoms, including neck stiffness, due to microangiopathic hemolytic anemia.
- Disseminated gonococcal infection: A rare condition that can cause a petechial rash and may involve the central nervous system, leading to symptoms like neck stiffness.
- Ehrlichiosis/Anaplasmosis: Tick-borne illnesses that can cause a petechial rash and may involve the central nervous system, although neck stiffness is less commonly reported.