What causes a scratchy throat and cough with yellow phlegm?

Itchy throat cough with yellow phlegm may be related to chronic sinusitis, acute upper respiratory tract infection, chronic allergic pharyngitis complicated by bacterial pneumonia and other diseases.
1. Chronic sinusitis: often caused by repeated episodes of acute sinusitis and abnormalities in the structure of the nasal cavity and sinuses, when the bacterial infection in the sinuses, there can be pus secretions, backflow into the throat cavity, manifested as yellow phlegm, stimulating itchy throat and cough and other discomforts.
2. Acute upper respiratory tract infection: viral or bacterial infection triggers acute inflammation of the nose, throat or larynx. There can be fever, headache, nasal congestion, runny nose, sore throat, cough, cough sputum and hoarse voice and other symptoms. Bacterial infection can cause yellow sputum.
3. Chronic allergic pharyngitis complicated by bacterial pneumonia: after repeated exposure to allergens, allergic patients may experience symptoms such as itchy throat and cough. Due to systemic and local resistance decline, excessive fatigue, malnutrition, upper respiratory tract infections and other factors induced by Staphylococcus aureus infection caused by pneumonia, the more typical cough sputum is yellow purulent.
When the occurrence of itchy throat cough with yellow sputum, can actively seek medical system diagnosis and examination.