What is the cause of itchy nose and sneezing?

Nasal itching is commonly associated with allergic rhinitis, but can also be seen in acute and chronic rhinitis, etc.
Itchy nose causes sneezing as a reflexive protective action in humans. The nasal mucous membrane nerves produce a sequential sharp deep inhalation after exposure to dust, allergenic pollen, irritating odours, cold stimuli on the body surface, etc., and a strong unconscious airflow ejects rapidly from the nasal and oral cavities to clear the nasal cavity of foreign objects or irritants, etc.
Repeated and frequent episodes of sneezing are a pathological phenomenon and an important symptom of certain nasal diseases.