Inhalation injury is a chemical injury to the respiratory tract caused by the inhalation of toxic fumes or chemicals, which can directly damage the lung parenchyma in severe cases. It occurs mostly in large areas, especially in patients with head and facial burns. Moderate inhalation injury refers to injury above the tracheal ridge, including the pharynx and trachea. Clinical manifestations include irritated cough, hoarseness, dyspnea, soluble carbon particles and detached tracheal mucosa in sputum, laryngeal edema leading to airway obstruction, and inspiratory stridor. The breath sounds on lung auscultation are weak or coarse, and occasionally croup and dry rales can be heard. Patients are often complicated by bronchitis and aspiration pneumonia. The following symptoms need to be distinguished from each other. Septic esophagitis Septic esophagitis is most commonly associated with mechanical injury caused by foreign bodies. Bacteria multiply in the esophageal wall, causing local inflammatory exudate, varying degrees of tissue necrosis and pus formation, and can also be more extensive cellulitis. 2. Esophageal tuberculosis Patients with esophageal tuberculosis usually have the first symptoms of tuberculosis in other organs, especially pulmonary tuberculosis. Symptoms in the esophagus itself are often confused or masked by symptoms in other organs, so that they cannot be detected in time. According to the pathological process of tuberculosis, the early infiltrative progressive stage may have toxic symptoms such as malaise, low fever, and increased blood sedimentation, but there are also those with no obvious symptoms. This is followed by dysphagia and progressive dysphagia, often accompanied by persistent pain in the throat and behind the sternum, which is aggravated by swallowing. Ulcerated lesions are mostly characterized by pain on swallowing. Spillage of food into the trachea should be considered as the formation of tracheoesophageal fistula. Difficulty in swallowing suggests scar stenosis due to lesion fibrosis. The clinical symptoms of fungal esophagitis are atypical, and some patients may not have any clinical symptoms. Common symptoms are painful swallowing, dysphagia, epigastric discomfort, retrosternal pain and burning sensation. In severe cases, the retrosternal pain is cut-like and can radiate to the back, resembling angina pectoris. Severe bleeding can occur in Candida esophagitis but is uncommon. Untreated patients may have epithelial detachment, perforation, or even disseminated candidiasis. Esophageal perforation can cause mediastinitis, esophagotracheal fistula and esophageal stricture. Patients with granulocytopenia with persistent hyperthermia should be examined for disseminated acute candidiasis of the skin, liver, spleen, and lungs.