The following conditions are associated with orbital cellulitis: 
Chronic sinusitis Upper respiratory tract infection Subperiosteal abscess
What is the underlying cause or mechanism of orbital cellulitis?
<|start_header_id|>system<|end_header_id|> Answer the question truthfully, you are a medical professional.<|eot_id|><|start_header_id|>user<|end_header_id|> This is the question: What is the underlying cause or mechanism of orbital cellulitis?<|eot_id|><|start_header_id|>assistant<|end_header_id|> The following conditions are associated with orbital cellulitis: 
Chronic sinusitis Upper respiratory tract infection Subperiosteal abscess<|eot_id|>