Polyhexamethylene guanidine phosphate (PHMG-P) is a guanidine-based disinfectant previously used in household humidifiers in Korea. This study evaluated whether PHMG-P exposure is causally linked to pneumonitis by integrating epidemiological, toxicological, and mechanistic evidence. We prespecified an evidence-integration framework aligned with the Office of Health Assessment and Translation/Grading of Recommendations Assessment, Development and Evaluation approaches, and applied the Organisation for Economic Cooperation and Development adverse outcome pathway (AOP) guidance to organize mechanistic evidence. We systematically identified studies and synthesized findings across 3 domains: epidemiology (age-period-cohort [APC], difference-in-differences [DID], and interrupted time-series [ITS] analyses), toxicology (animal and in vitro studies), and mechanism (mapping key events to an AOP). We assessed internal and external validity, coherence, and strength of evidence within and across domains. Epidemiological analyses showed that pneumonitis incidence rose during humidifier disinfectant use and declined after the 2011-2012 withdrawal, with higher risks in children and reproductive-age females. APC, DID, and ITS, including PHMG-P-specific time-series analysis, indicated increased pneumonitis incidence and mortality during exposure periods. Toxicological studies demonstrated that PHMG-P exposure resulted in epithelial injury, inflammation, fibrosis, and impaired lung function consistent with chemical pneumonitis. Mechanistic evidence linked PHMG-P exposure to epithelial damage, oxidative stress, macrophage polarization, and fibrotic changes. Multiple lines of evidence support a causal link between PHMG-P exposure and pneumonitis, underscoring the value of integrating epidemiology and toxicology to strengthen risk assessment and inform policy.

Abstract Lipoid pneumonitis is a rare, albeit deadly, condition if not identified and managed in time. Although the overall incidence has reduced significantly, it still remains an area of concern among the armed forces deployed in cold and high altitude areas and professional “fire-eaters.” This case series examined seven instances of chemical pneumonitis caused by accidental kerosene (and diesel in one instance) ingestion in adult males over 1 year. The patients had presented with vomiting, nausea, cough, and pleuritic chest pain following the ingestion, which occurred primarily while siphoning fuel. The clinical findings included tachycardia, tachypnea, and crackles on auscultation. Chest radiographs typically showed right lower zone opacities. Management involved supportive care, with antibiotics administered in some cases. All patients recovered within 10–15 days, although some experienced persistent chest pain. This study highlights the ongoing risk of kerosene-induced pneumonitis, particularly in occupational settings, and emphasizes the importance of prompt recognition and treatment. It also underscores the need for increased awareness and preventive measures to reduce such accidents.

Chemical pneumonitis in a pediatric emergency: Case Report of cocoa powder aspiration

Community-acquired pneumonia (CAP) is a condition with high morbidity and mortality, particularly among users of inhaled drugs. The use of the synthetic drug K9 (spice) has been associated with chemical pneumonitis, whose clinical presentation can mimic respiratory infections, complicating diagnosis and appropriate management. This study reports the case of a 33-year-old male patient with a history of substance dependence and recent K9 use, who was hospitalized with severe respiratory failure. Laboratory tests, chest computed tomography, and microbiological and molecular analyses for infectious agents were performed. Initial treatment included empirical antibiotic therapy, invasive ventilatory support, and systemic corticosteroids. The absence of identifiable pathogens and compatible radiological findings led to the diagnosis of K9-induced chemical pneumonitis. Corticosteroid therapy resulted in progressive clinical improvement, allowing extubation and hospital discharge after 24 days, with referral for rehabilitation. This case highlights the importance of considering synthetic drugs in the differential diagnosis of CAP in young individuals with a history of substance use, preventing unnecessary antibiotic use and ensuring more targeted treatment. Additionally, it underscores the need for professional training to recognize clinical and radiological patterns suggestive of chemical pneumonitis, as well as the development of public policies aimed at preventing synthetic drug use and mitigating its impact on public health.

The term "aspiration" describes lung injury that results from unintentional passage of contents other than air into the lungs and bronchial tree, commonly from the gastrointestinal and upper respiratory tracts. Only a small proportion of aspiration-related events are symptomatic, especially in predisposed individuals such as patients with diminished consciousness, impaired swallowing, oesophageal motility disorders, and reflux disease. Aspiration-related syndromes can be classified based on the onset of presentation, composition of the aspirated substance, and anatomic site of injury. When considering the injury site, the aspirated material can either obstruct the airways, thereby presenting with obstructive features (eg, atelectasis on radiographs); it can alternatively affect the lung parenchyma. Lung injury due to aspiration of noxious agents such as acid or lipids is termed chemical aspiration pneumonitis. The aspirated contents can alternatively lead to lung parenchymal infection when the contents are infected, which is termed aspiration pneumonia. We have reviewed the imaging manifestations of various entities related to aspiration and have classified the abnormalities based on the site of injury and the nature of the culprit agent. Differences between "aspiration pneumonitis" and "aspiration pneumonia" are also explored. This is followed by an illustration of a few specific situations related to aspiration in pediatric and adult patients.

Toxic pneumonitis in the context of cabergoline treatment

Introduction: Chemical pneumonitis is an uncommon condition. Hydrocarbon pneumonitis is a kind of chemical pneumonitis. The features of this disease are atypical and may manifest either abruptly or persistently. Lung tuberculosis is an endemic illness in Indonesia, with an estimated 969,000 patients exhibiting diverse characteristics that may resemble chemical pneumonitis. Case Report: A 29-year-old gas station attendant with a history of recurrent exposure to gasoline vapours and episodes of asphyxiation while syphoning gasoline. A thoracic CT scan with contrast reveals several bilateral nodules with a tree-in-bud pattern, suggestive of pulmonary tuberculosis, with chemical pneumonitis as a differential diagnosis. Utilising clinical data, including occupational history, body plethysmography and spirometry results (moderate restrictive), laboratory findings, CT scan pictures, and Volatile Organic Compound analysis (elevated hydrocarbon levels), the patient is diagnosed with hydrocarbon pneumonitis. Discussion: The differential diagnosis was excluded through the analysis of sputum using molecular rapid test, IGRA test, LJ culture, and AFB of bronchial washing fluid. The administration of inhaled corticosteroids is a viable therapeutic option for this situation. Following six months of medication and exposure avoidance, the patient's condition has been improving. The patient was initially diagnosed with suspected lung tuberculosis based on a thoracic CT scan with contrast revealing bilateral multiple nodules exhibiting a tree-in-bud pattern. However, considering the patient's occupational history involving exposure to gasoline vapour and a history of choking on gasoline, the radiological findings ultimately confirmed a diagnosis of hydrocarbon pneumonitis. Case management may be determined by the severity level; however, due to its rarity, no primary treatment option exists. Conclusion: Hydrocarbon pneumonitis is infrequently encountered in comparison to pulmonary tuberculosis. Inhaled corticosteroids are a treatment alternative that yields clinical improvement. This example illustrates those rare diseases, such as hydrocarbon pneumonitis, can mimic pulmonary tuberculosis.

This article analyzed the use of veno-arterio-venous extracorporeal membrane oxygenation (VAV-ECMO) in the treatment of a patient with severe cardiopulmonary insufficiency caused by inhalation of dilute nitric acid liquid and aerosol. Combined with relevant literature, the pathogenesis was discussed and the treatment experience was summarized. The inhalation of a large amount of dilute nitric acid liquid and aerosol caused severe chemical pneumonia in the patient, which resulted in severe cardiac insufficiency due to the dysregulation of the ventricular artery coupling. After the administration of VAV-ECMO, the well-oxygenated blood was effectively supplied to the systemic circulation and pulmonary circulation, and the load of the heart was reduced, providing valuable time for the recovery of the patient's cardiopulmonary function.

This report presents two cases of chemical pneumonitis caused by the exposure of sodium ibandronate powder, a bisphosphonate used for treating osteoporosis. They are both pharmaceutical workers, and they inhaled the powder after an accidental spill in the lab. They developed similar symptoms, but different imaging features, only one showed fibrotic changes. After the blood test and bronchoscopy examination, they both diagnosed as chemical pneumonitis. Their symptoms improved after treatment with glucocorticoids. Their lung lesions resolved completely after continued treatment. The findings suggest that the importance of appropriate safety measures in environments where pharmaceutical powders may be handled, such as in the pharmaceutical industry. Chemical pneumonitis from inhaled sodium ibandronate can have varying CT appearances and may benefit from glucocorticoids therapy.

Chemical Pneumonitis from a Swimming Pool Disinfectant Exposure in a 13-Year-Old Male: A Case Report.

Chemical Pneumonia Associated with Electronic Cigarette Use: An Article Review

Historically, different types of explosives have been used in mining. Black gunpowder is the most widely used, comprising carbon, sulfur, and potassium nitrate. Knowing that the fumes emitted after an explosion are highly toxic is essential. Chemical pneumonitis resulting from the inhalation of pyrotechnic smoke (black powder) is associated with the various products of its combustion, where potassium compounds are predominant and highly toxic. We report the case of a man in his third decade of life who, working as a miner, was exposed to the inhalation of white smoke from black powder for an approximate time of 10 minutes with the subsequent appearance of signs of respiratory difficulty and pulmonary involvement that was demonstrated. Through imaging (x-ray and chest tomography), bilateral inflammatory lung involvement at the interstitial level is observed secondary to inhaled toxins, and after the initiation of early corticosteroid therapy, adequate resolution of the interstitial lung involvement is documented, accompanied by an adequate clinical and respiratory response.

Chemical pneumonitis secondary to ingestion/inhalation of corrosive substances- Ethylenedioxy Dimethanol & Glutaraldehyde

Dysphagia is a frequently underdiagnosed consequence of dementia (up to 95%) (Dziewas & Pflug et al. 2020), which often goes unnoticed by those around the patient and is probably not always recognised by those affected, and is the cause of a higher risk of complications and life-threatening conditions (Baijens 2016, Namasivayam & Steele 2015): Dysphagia-related malnutrition and dehydration as well as aspiration pneumonia and the need for enteral feeding, among other things, lead to increased and repeated hospital admissions with stressful interventions, longer hospital stays and the likelihood of being discharged to rehabilitation facilities and nursing homes instead of home after hospitalisation (Altmann 2010). Even medication taken with the intention of improving the condition becomes a risk: chemical pneumonitis is the result of aspirated medication, leading to odynophagia due to mucosal damage in the swallowing route, viral or fungal-associated oesophagitis due to immunosuppressants. Compensatory functions can be impaired, particularly in old age and as a result of multiple medications (Schwemmle et al. 2015). Untreated pneumonia can also exacerbate existing coronary heart disease and trigger other acute cardiac syndromes or death from sepsis.

The development of classification-based machine-learning models for the toxicity assessment of chemicals associated with plastic packaging

Historically, different types of explosives have been used in mining. Black gunpowder is the most widely used, composed of carbon, sulfur, and potassium nitrate. Knowing that the fumes emitted after an explosion are highly toxic is essential. Chemical pneumonitis due to inhalation of pyrotechnic smoke (black powder) is associated with the different products of its combustion, where potassium compounds are dominant and very toxic. We report the case of a man in his third decade of life who, working as a miner, was exposed to the inhalation of white smoke from black powder for an approximate time of 10 minutes with the subsequent appearance of signs of respiratory difficulty pulmonary involvement that was demonstrated. Through images (x-ray and chest tomography) with bilateral inflammatory lung involvement at the interstitial level secondary to inhaled toxic and after the start of early corticosteroid therapy, in tomographic control, adequate resolution of the interstitial lung involvement is recorded by adequate clinical and respiratory response.

Comprehensive management of bronchobiliary fistula with consequent chemical pneumonia : a case report

Aspiration represents the passage of oropharyngeal content to the lower respiratory tract. The interplay between the host and the aspirate proprieties determines the subsequent aspiration syndrome. A low pH, typical of gastric aspirate, favors chemical pneumonitis, whereas an increased bacterial inoculum causes aspiration pneumonia. About a quarter of patients with aspiration pneumonitis will develop a bacterial superinfection during the course of recovery. While antibiotic therapy is indicated for aspiration pneumonia, supportive care remains the cornerstone of treatment in aspiration pneumonitis. However, the overlapping clinical features of these syndromes lead to initiation of antimicrobial therapy in most cases of aspiration. Bronchoscopy can aid in clinical decision-making by direct airway visualization and also by providing access to a series of emerging biomarkers. Invasive microbiological studies increase diagnostic yield and enable a tailored antibiotic treatment. In conjunction with stewardship programs, invasive sampling and novel molecular diagnostics can decrease the amount of inappropriate antibiotic therapy. In the context of foreign body aspiration, bronchoscopy represents both diagnostic and treatment gold standard.

Hydrocarbon poisoning, particularly from accidental ingestion, is a significant risk for children and often lead to chemical pneumonitis and severe respiratory complications. This case report describes a 12-year-old boy with intellectual disability who ingested petrol, leading to chemical pneumonia complicated by pleurisy detected through chest CT scans. This case underscores the importance of timely imaging in managing hydrocarbon poisoning and highlights the need for preventive strategies to reduce such incidents in children.

Abstract Paint thinners are organic hydrocarbons that contain a mixture of chemicals such as acetone, toluene, and xylene. Thinner poisoning is most common in children due to accidental ingestion. Acute poisoning can lead to various systemic manifestations such as chemical pneumonitis, arrhythmia, dermatitis, and metabolic acidosis. Chronic toxicity leads to encephalopathy and weakness. Usually, management of chemical pneumonitis following hydrocarbon aspiration is symptomatic and the role of steroids is controversial. We report the case of a 47-year-old female who presented with ingestion of paint thinner with suicidal intention and developed chemical pneumonitis. She was initially managed symptomatically but due to persistent symptoms, was started on intravenous steroids and antibiotic. The patient showed symptomatic and radiological resolution.