In the diagnostic statement "Chronic allergic sinusitis due to animal dander",the modifying terms are;
CHRONIC AND ALLERGIC.
A diagnostic statement states the potential and actual health problem of a client. These client's problems are the ones the nurse or the person making the diagnosis can actually identify easily and also for which order and implement nursing interventions inorder to maintain the health status if the client,and to eliminate, prevent or rather reduce changes and alterations in the patient's health status.
So from the question given, the modifying terms from the diagnostic statement "Chronic Allergic Sinusitis" is Chronic and Allergic.