A 9-year-old female patient was admitted to the hospital, presenting with a 7-day history of sore throat, cough, and high fever that did not respond to antipyretic medications. She had received outpatient treatment with azithromycin for three days prior to admission. Despite medical management, her condition deteriorated, characterized by lethargy, increased cough frequency, persistent fever, and difficulty in swallowing liquids and solids. The patient's medical history revealed a diagnosis of achalasia at four years of age, which had not been treated. Upon admission, she exhibited severe malnutrition (weighing 19 kg, BMI – 11.2 kg/m2, indicating severe and prolonged malnutrition) and constipation due to inadequate nutrient intake. Early symptoms included hyperthermia, respiratory failure, and low oxygen saturation levels (SpO2 – 84-86% without oxygen supplementation). Severe vomiting ensued, leading to an inability to consume fluids and solid food, resulting in severe dehydration.
 

Her laboratory tests revealed anemia (Hemoglobin – 107 g/l, Hematocrit – 33.3%, Mean Corpuscular Volume – 64.3), a negative rapid test for COVID-19, chest X-ray showed infiltration in the right lower lobe and fibrous lung parenchyma, and markedly increased C-reactive protein levels (122.3 mg/l). Abdominal ultrasound showed pseudolithiasis, possibly related to treatment with ceftriaxone. (Onset of pseudobiliary stones varies from 2 to 22 days after starting treatment with ceftriaxone) Sputum sample results indicated Staphylococcus aureus and fungal infection; because of this, antifungal medication was added to the treatment. Due to the persistent fever and low oxygen saturation, we decided to perform a chest CT scan. This decision was based on the patient's deteriorating general condition, worse than what could be assessed through auscultation and radiologic changes seen on X-ray. Additionally, upon receiving the results of the antibiotic susceptibility testing (antibiogram), we opted to switch from ceftriaxone to piperacillin-tazobactam.  
 

Taking into account the patient's medical history, along with laboratory and radiographic analyses, the diagnosis was confirmed as aspiration pneumonia as a complication of esophageal achalasia.
 

Chest CT revealed infiltrations, especially in the lower right lobe, with bronchodilation on the same side and mild pleural effusion. An esophageal x-ray revealed an enlarged diameter of the esophagus, and emptying of the esophagus from contrast was delayed up to 15 minutes. As the patient was already unable to swallow fluids or solids and had forceful vomiting, their general condition worsened, and severe dehydration appeared; the team placed a nasogastric tube for proper feeding. A cardiologist excluded any severe cardiac abnormality. Over the past five years, she experienced persistent vomiting, regurgitation, and intermittent sub-febrile temperature.
 

The final diagnosis was esophageal achalasia grade III. After ten days of treatment, expectations included stabilization of respiratory function, resolution of pneumonia with appropriate antibiotic therapy, and improvement in nutritional status through high-calorie intake. After stabilization, surgical treatment was performed without complications.