Abstract
Hiccups are commonly benign, self-limiting events often triggered by transient gastrointestinal or central nervous system irritants. However, when persistent, they may indicate underlying pathology involving the thoracic, gastrointestinal, or neurological systems. We report the case of a 65-year-old male smoker who presented with a 4-day history of persistent hiccups. He denied fever, chest pain, hemoptysis, or other systemic symptoms. Physical examination was largely unremarkable except for decreased air entry in the right middle and lower lung zones. Initial investigations, including gastroscopy and tumor markers, ruled out gastrointestinal causes. CT scan of the chest revealed a right lower lobe consolidation and cavitation with air fluid level and adjacent ground-glass opacities, along with enlarged subcarinal lymph nodes. Differential diagnoses included lung abscess, pneumonia, and tuberculosis cavitation. The patient was admitted for suspected lung abscess and received antibiotics. Bronchoscopy with bronchoalveolar lavage revealed no endobronchial lesions, and PCR testing and culture of the fluid was negative for tuberculosis but positive for klebsiella pneumonia. Despite radiologic regression of pneumonia, the cavitary lesion and lymphadenopathy persisted initially, but later started to regress. This case highlights an unusual presentation of lung abscess manifesting solely as persistent hiccups, without classic respiratory or systemic signs. We aim to emphasize the need to consider thoracic causes in patients with otherwise unexplained persistent hiccups, and undergo further evaluation in such cases.
Learning Points
Persistent hiccups may be the sole presenting symptom of serious thoracic pathology, including lung abscess, even in the absence of fever or respiratory symptoms.
Comprehensive evaluation, including imaging and microbiological testing, is essential to identify the underlying cause and guide targeted therapy.
Introduction
Hiccups are involuntary contractions of the diaphragm and intercostal muscles, followed by abrupt laryngeal closure, producing the classic “hic” sound. While usually harmless and short-lived, hiccups lasting over 48 hours are termed persistent, and those exceeding 2 months are intractable. They result from a reflex arc involving 3 components: afferent pathways, a central midbrain processor, and efferent fibers to respiratory muscles. Disruption along this arc, either structurally or functionally, can trigger prolonged or recurrent hiccups.1,2 Hiccups has been associated with several causes including central, gastrointestinal and thoracic pathologies.1,2 A lung abscess is a localized collection of pus or necrotic debris within the lung parenchyma, resulting in a cavity filled with fluid and infectious material. It can be classified as acute and chronic, and primary or secondary based on its cause. A patient with lung abscess may present with fever, chills, night sweats, cough, weight loss and hemoptysis. 3 If present in the lower lobe of the lung, the abscess or any lung cavitation can irritate the phrenic nerve causing hiccups. While hiccups can be a manifestation of lung abscess, it usually presents with systemic symptoms. However, hiccups as a sole presenting symptom of abscess has rarely been reported to our knowledge. We present a 65-year-old male smoker who presented with persistent hiccups. He had no systemic or respiratory symptoms. Physical exam was unremarkable except for reduced air entry in the right lung. Initial workup ruled out gastrointestinal malignancies and infections. Chest computed tomography (CT) Scan revealed a right lower lobe cavitary lesion with air fluid level and ground-glass infiltrates along with enlarged subcarinal lymph nodes. He was diagnosed with a lung abscess and started on antibiotics, with initial improvement in C-reactive protein (CRP). Bronchoscopy and fluid PCR were negative for tuberculosis but positive for klebsiella pneumonia. The pneumonia and lung abscess started regressing progressively after starting antibiotics and the patient started reporting improvement in his symptoms.
Case Presentation
A 65 years old male patient with no previous medical history, presented for hiccups of 4 days duration. He reported no fever, chills, cough, chest pain, hemoptysis, or night sweats. He smokes 1 pack of cigarettes per day and has an allergy to penicillin. On physical exam, his vital signs were stable. Lung auscultation was significant for mildly decreased air entry on the right middle and lower lobes. His abdomen was soft and no lower limb edema was present. Among the differential diagnosis proposed are gastroesophageal reflux, esophageal cancer, gastric cancer and pancreatic cancer. Gastroscopy done as out was negative for any gastroesophageal diseases. CA 19-9 was negative as well. Chest Xray was done showing absence of pleural effusions, right lower lobe infiltrates infectious in nature, and no cardiomegaly (Figure 1). CT scan of the chest was ordered for further investigations. Result was significant for a right lower lobe posterior segment consolidation with adjacent ground glass infiltrates and internal cavitation measuring around 2.8 cm with air fluid level, and enlarged mediastinal lymph nodes, mainly in the subcarinal area (Figure 2). The patient was admitted for lung abscess management. Given the patient’s age and smoking history, malignancy was considered in the differential diagnosis. During his stay, the patient was afebrile, reported no new-onset productive cough. Laboratory results were significant for a high WBC of 11.52 × 10^9/L with neutrophil predominance, and CRP of 297 (Table 1). The patient was initially started on intravenous piperacillin–tazobactam (4.5 g every 6 hours), which was discontinued after 1 day due to an allergic reaction. Initial improvement of CRP was seen from 297 to 171. He was subsequently switched to intravenous levofloxacin; however, after 48 hours, given persistently elevated inflammatory markers and the severity of the cavitary process, antimicrobial therapy was escalated to intravenous tigecycline. He also underwent bronchoscopy with bronchoalveolar lavage, showing no endobronchial lesions or extrinsic compression. Bronchoalveolar lavage PCR identified Klebsiella pneumoniae, with susceptibility testing demonstrating sensitivity to fluoroquinolones. Cell cytology was negative for malignancy and atypical cells. Fluid PCR was negative for viruses and mycobacterium tuberculosis and non-tuberculosis. Tigecycline was continued for 2 weeks, during which the patient showed marked clinical and biochemical improvement. CRP started trending down reaching a value of 26. He was then transitioned to oral levofloxacin upon discharge to complete a total of 6 weeks of antimicrobial therapy. This step-down strategy was guided by susceptibility results, clinical stabilization, and established management principles for lung abscess. A follow up CT scan of the chest, abdomen and pelvis was ordered after 7 days of admission, showing regression of the pneumonia, with persistence but decreased cavitation and mediastinal lymph nodes (Figure 3). As the follow-up CT after completion of antibiotic therapy demonstrated regression of the lymphadenopathy, this supported a reactive inflammatory process rather than a malignant process. Also, no significant finding of infections or metastasis were seen in the abdomen. Regarding the lung cavitation, differentials proposed were tuberculosis, lung abscess. Tuberculosis was ruled out. We were left with the diagnosis of lung abscess with underlying pneumonia. A repeat CT scan after completion of therapy showed near-complete resolution, supporting adequate treatment response (Table 2).
Chest Xray showing absence of pleural effusion, a right lower lobe infiltrate, infectious in nature, and no cardiomegaly.
CT scan of the chest showing a right lower lobe posterior segment consolidation with adjacent ground glass infiltrates and internal cavitation measuring around 2.8 cm with air fluid level, and enlarged mediastinal lymph nodes, mainly in the subcarinal area.
Laboratory results on admission.
CT scan of the chest showing regression of the pneumonia with persistent but decreased cavitation and mediastinal lymph nodes.
Clinical timeline of the patient with lung abscess presenting as persistent hiccups.
Abbreviations: BAL, bronchoalveolar lavage; RLL, right lower lobe.
Timeline outlines the onset of symptoms, key investigations, changes in antibiotic therapy, CRP trends, and imaging follow-up. CRP values are reported in mg/L. Arrows (↑/↓) indicate rising or declining trends.
Discussion
Hiccups are sudden, involuntary contractions (myoclonus) of the diaphragm and intercostal muscles, immediately followed by closure of the larynx. This abrupt closure produces the characteristic “hic” sound as air rushes into the lungs. In most cases, hiccups are benign and self-limiting, resolving on their own without clinical significance. Episodes lasting 48 hours or more are classified as persistent hiccups, while those persisting for over 2 months are considered intractable. The underlying mechanism involves a neurological reflex arc made up of 3 components. An afferent limb, which includes the phrenic, vagus, and sympathetic nerves transmitting somatic and visceral sensory signals. A central processing center located in the midbrain. An efferent limb, consisting of the motor fibers of the phrenic nerve to the diaphragm and accessory nerves to the intercostal muscles. Disruption or irritation affecting any part of this reflex arc—whether structural or functional—can contribute to the development of intractable hiccups.1,2
Several conditions have been associated with the development of intractable or persistent hiccups. Central causes related to the central nervous system include strokes, brain tumors, multiple sclerosis, trauma and seizures. 2 Regarding the cardiothoracic system, mediastinal diseases, lymphadenopathies, myocardial ischemia, pneumonia, empyema, pleuritis, aortic aneurysm, chest trauma, pulmonary embolism, diaphragmatic tumors have been linked to persistent hiccups.1,2
A lung abscess is a localized collection of pus or necrotic debris within the lung parenchyma, resulting in a cavity filled with fluid and infectious material. 10 When a bronchopulmonary fistula develops, an air-fluid level typically appears within this cavity. It belongs to a group of pulmonary infections, including lung gangrene and necrotizing pneumonia, the latter often presenting with multiple abscesses. 3 According to Moreira, José da Silva, et al., lung abscesses most commonly develop in the apical segment of the lower lobes or the posterior segment of the right upper lobe, which lie in close proximity to the diaphragm. Lung abscesses are classified as acute if they persist for less than 6 weeks, and chronic if they last longer. They may be considered primary when caused by aspiration of oropharyngeal secretions, often associated with dental or periodontal infections, paranasal sinusitis, impaired consciousness, swallowing difficulties, gastroesophageal reflux, frequent vomiting, necrotizing pneumonias, or in individuals with compromised immune systems. 3 The early signs and symptoms of a lung abscess are often indistinguishable from those of pneumonia and typically include fever with chills, cough, night sweats, shortness of breath, weight loss, fatigue, chest pain, and occasionally anemia. Initially, the cough is dry, but once a connection forms between the abscess and a bronchus, it becomes productive—a classic finding known as vomica. 3 Surgical resection is required in approximately 10% of cases, with indications categorized as acute or chronic. Acute indications include massive hemoptysis, persistent sepsis with ongoing fever, bronchopleural fistula, and rupture of the abscess into the pleural space leading to pyopneumothorax or empyema. 3
In the thoracic cavity, the right lower lobe of the lung lies in close proximity to the diaphragm, and inflammatory processes such as a lung abscess can directly irritate the diaphragm or the terminal branches of the right phrenic nerve, which courses along the pericardium and mediastinum before innervating the diaphragm. Localized inflammation, edema, or mass effect from the abscess may mechanically stimulate or sensitize the phrenic nerve, thereby triggering repetitive diaphragmatic contractions. This explains why lower lobe pulmonary pathology, even in the absence of classic systemic or respiratory symptoms, can manifest solely as persistent hiccups.
An additional system linked to hiccups is the gastrointestinal and digestive system which include esophageal tumors, GERD, H. pylori infection, pancreatitis, pancreatic cancer, gastric carcinoma, abdominal abscesses, gallbladder disease.1,2 Moreover, some drugs and chemotherapeutic agents along with instrumentation procedures have been associated with the development of hiccups. 2 Hiccups can lead to a variety of complications including difficulty in feeding, discomfort, GERD, respiratory alkalosis, sleep deprivation and psychiatric disorders. 1 Treatment of hiccups has not been well established in guidelines. The treatment options for hiccups are pharmacological and non-pharmacological. Pharmacological therapy includes chlorpromazine, gabapentine, baclofen, midazolam, olanzapine, 2 haloperidol, metoclopramide, amitriptyline and amantadine diphenylhydantoin, valproic acid, nifedipine, mephenesin, and orphenadrine.1,4
Non-pharmacological approaches used to manage persistent and intractable hiccups include: ultrasound-guided phrenic nerve blockade for post-operative and lung cancer-related hiccups, left vagal nerve stimulation particularly in stroke-related cases, and ultrasound-guided pulsed radiofrequency ablation of the phrenic nerve for hiccups following coronary bypass surgery. Ultrasound (US) guided pulsed radiofrequency treatment (PRFT) of right phrenic nerve has also been used to treat lung cancer induced hiccups in a case reported by Cho 5 Acupuncture has also proven beneficial in patients with myocardial infarction, metastatic liver tumors, and stroke-related hiccups. 2 In addition, recommended treatments for transient, self-limited hiccups include nasopharyngeal stimulation, vagal stimulation and respiratory maneuvers.1,5 Respiratory maneuvers associated with hiccup suppression include breathholding, neck extension, quickly drinking a large glass of water, steady inspiratory effort against a closed airway, application of 20 to 40 cmH2O CPAP, coughing, hyperventilation, rebreathing in a bag or breathing a 5% CO2 mixture, compression of the diaphragm by drawing the legs up or leaning forward, compression of the thyroid cartilage, and application of ice or mustard plaster on the epigastrium. 4
Several cases of hiccups caused by pulmonary diseases have been reported. 6 Modi and Lenox, reported 2 cases of pulmonary mycobacterium tuberculosis causing a lung mass in the lower lobe and mediastinal lymphadenopathy that presented with fever and hiccups. Hiccups subsided after starting anti-tuberculosis therapy. 6 Lower lobe pneumonia was also found to present with persistent hiccups as a sole symptom, however a history of aspiration and vomiting event was reported prior to development of symptoms. 7 Furthermore, empyema was found to present as unexplained fever with persistent hiccups. 8 Hilar and mediastinal lymph node enlargement have been found to cause persistent hiccups in a patient with sarcoidosis. 9 One case of lung abscess induced hiccups has been described in which the patient presented with a 4-day history of persistent hiccups, right-sided chest pain, and multiple episodes of fever. 10 Karakonstantis et al describe a case of pneumonia in an elderly patient who presented with persistent hiccups as a sole symptom, and was confirmed on CT scan, raising the importance of considering lung pathologies for hiccups in elderly patients. 11
In our case, the patient had no signs of neurological deficit or history of central nervous system disorder, ruling out Central causes. Then, gastroesophageal diseases were ruled out with a normal finding on gastroscopy. The patient takes no home medications and has no history of instrumental procedures. Therefore we were left with thoracic origin of hiccups. In contrast to other cases of hiccups caused by pulmonary diseases, our patient presented with hiccups as his only symptom with no respiratory symptoms or signs of infection. Therefore, our incidental finding of lung cavity with air fluid level surrounded by lobar pneumonia was interesting. After ruling out tuberculosis, we were left with a diagnosis of lung abscess induced hiccups and malignancy. An important feature of this case is the marked elevation of inflammatory markers in the absence of fever. While fever is a common manifestation of lung abscess, its absence does not exclude significant infection, particularly in older adults who may exhibit a blunted systemic inflammatory response. The markedly elevated CRP at presentation (297 mg/L) reflected substantial localized inflammatory activity despite the lack of constitutional symptoms. Importantly, the progressive decline in CRP levels closely paralleled the resolution of the patient’s hiccups following appropriate antibiotic therapy. This temporal association strengthens the hypothesis that diaphragmatic irritation secondary to the inflammatory process was the underlying trigger of the hiccups. The presence of mediastinal lymphadenopathy in an elderly smoker initially raised concern for malignancy. However, the radiological resolution following antibiotic therapy strongly supported a reactive etiology secondary to the infectious process rather than an underlying neoplastic condition. Clinical improvement started to be seen along with radiological findings. We aim to raise awareness about not neglecting persistent hiccups and keep in mind lung pathologies in our differential diagnosis.
Conclusion
This case underscores the diagnostic value of persistent hiccups as a potentially sole presenting symptom of serious pulmonary pathology. Unlike prior reports, our patient exhibited no respiratory or systemic signs, with hiccups being the only clinical clue leading to the incidental discovery of a lung abscess. While hiccups themselves do not directly cause lung abscess formation, persistent or intractable hiccups may predispose patients to aspiration events, thereby increasing the risk of aspiration pneumonia and, in severe or untreated cases, secondary lung abscess development. As hiccups can be possibly a predisposing cause for lung abscess formation, they can be on the other hand a presenting symptom of lung abscess. In our case, hiccups alone prompted further imaging, ultimately revealing a cavitary lung lesion. We highlight the need for clinicians to maintain a high index of suspicion and to consider thoracic etiologies in atypical presentations, ensuring that seemingly benign symptoms like hiccups are not overlooked.
Footnotes
Ethical Considerations
Case reports are exempted from ethical approval at our institution
Consent to Participate
A signed written informed consent was obtained from the patient prior to manuscript submission
Authors Contributions
Conceptualization, Elias Fiani; writing—original draft preparation, Antonio Al Hazzouri, Philippe Attieh, Karam Karam, Ihab I. El Hajj, Said G. Farhat, Elias Fiani; writing—review and editing, Antonio Al Hazzouri, Philippe Attieh, Karam Karam, Ihab I. El Hajj, Said G. Farhat, Elias Fiani; supervision, Elias Fiani; project administration, Elias Fiani. All authors have read and agreed to the published version of the manuscript
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
Data will be made available upon request from authors.