Aspiration of zinc tablet leading to chemical burn of the airway: Case report : Medicine: Case Reports and Study Protocols

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Clinical Case Report

Aspiration of zinc tablet leading to chemical burn of the airway

Case report

Qian, Edward T. MDa,∗; Lentz, Robert J. MDa,b; Johnson, Joyce MDc; Maldonado, Fabien MDa,b

Author Information
Medicine Case Reports and Study Protocols: February 2022 - Volume 3 - Issue 2 - p e0214
doi: 10.1097/MD9.0000000000000214
  • Open


1 Introduction

During the Novel 2019 Coronavirus Disease (COVID-19) pandemic, a number of people have turned to home remedies for the treatment and prophylaxis including zinc.[1] Inhalation of zinc-containing fumes and powders has been reported in the past to cause what we now consider chemical pneumonitis.[2] We present a case of aspiration of a supplementary zinc tablet leading to a circumferential fibroinflammatory chemical burn. To our knowledge, this is the first report of this kind.

2 Case report

A 73-year-old woman with a history of burning mouth syndrome (severe dry mouth) and gastroesophageal reflux disease presented for bronchoscopy after aspiration of a zinc supplement tablet. She was taking a zinc supplement prophylactically for COVID-19. She had progressive dysphagia over several years due to burning mouth syndrome. Ten days prior to her presentation, she attempted to swallow her supplement and immediately developed a choking sensation associated with violent coughing, dyspnea, and chest pressure. She presented to her local emergency room and underwent a chest radiograph that did not reveal any obvious abnormality and was discharged home without steroids (Fig. 1). Her severe cough persisted, prompting interventional pulmonary consultation to consider bronchoscopic evaluation for possible foreign body removal.

Figure 1:
Original Chest X-Ray. Essentially normal chest x-ray with known calcified granuloma seen in the left hilum.

A flexible bronchoscopic airway examination (Olympus USA, Center Valley, Pennsylvania) revealed a circumferential ulcerative and fibroinflammatory mucosal injury affecting the right lower lobe common basilar bronchus immediately distal to the origin of the superior segment, suggestive of a chemical burn secondary to the aspirated and dissolved zinc pill (Fig. 2). The airway was not stenotic. The airway mucosa was normal distal to the stenotic area. Four endobronchial biopsies of the abnormal region were obtained and sent for histopathology, which revealed ulcerated and necrotic respiratory mucosa with adherent fragments of foreign material (Fig. 3). Despite the lack of visualization of the aspirated pill, this histopathology is similar to reports of other pill aspiration such as iron[3] and in the clinical context was consistent with airway inflammation from zinc exposure. The patient was discharged after two weeks of steroid therapy.

Figure 2:
Initial Videobronchoscope images. A P190 Olympus Videobronchoscope was used to obtain the pictures. This demonstrates a circumferential, fibroinflammatory lesion in the right lower lobe common basilar bronchus just distal to the superior segment take-off.
Figure 3:
Pathology Images. 4 endobronchial biopsies were taken in the right lower lobe. Left pane: Biopsies showed ulcerated and necrotic mucosa with adherent fragments of foreign material (between arrows; H&E at 20x). Right pane: Two types of foreign material were present: abundant translucent polarizable material (polarized H&E at 10x), and a few larger pieces of dark purple-staining glassy material (inset; same field, H&E at 10x).

At follow-up, repeat bronchoscopy six weeks later revealed that the same area was concentrically narrowed to approximately 2 to 3 mm with evidence of granulation tissue. A 1.9 mm cryoprobe (Erbe, Tübingen, Germany) was used to circumferentially cryoablate the stenotic region using five freeze-thaw cycles of 10 seconds each. The stenosis was then balloon-dilated to 8 mm with excellent endoscopic results (Fig. 4).

Figure 4:
Follow-up Videobronchoscope Images. The prior area of inflammation progressed to circumferential narrowing despite steroid therapy. This was dilated using a 1.9 mm Erbe cryoprobe and 8 mm balloon with excellent visual result.

3 Discussion

Zinc pill aspiration resulting in bronchial chemical burns has not been previously reported. There have been multiple case reports of other mineral supplements causing airway edema and stenosis from iron, potassium, and multivitamin pills.[4–6] Other elemental metal aspirations have been reported to cause no mucosal damage, such as calcium.[7] The only extant literature regarding the effect of zinc in the airway is on the inhalation of zinc chloride fumes or zinc stearate powder. These small particulates are able to penetrate further into the tracheobronchial tree, causing what we now consider chemical pneumonitis ranging in severity up to acute respiratory distress syndrome leading to death.[2] Since our patient aspirated a pill, the inflammation and damage were limited to a large airway.

Central airway obstruction is defined as occlusion of the trachea, mainstem bronchi, bronchus intermedius, or lobar bronchus, and severity is graded by the degree of obstruction.[8] There is no consensus grading system, but our patient had < 25% obstruction, which progressed to between 75% and 90%. Surgical resection is the therapy of choice for patients with symptomatic, benign tracheal strictures; however, the optimal management of strictures in the lower tracheobronchial tree is unclear. Endoscopically, techniques such as laser or electroresection, balloon dilation, and cryo-recanalization can provide immediate relief, but long-term efficacy is unknown, and a multidisciplinary approach between thoracic surgery and interventional pulmonary is recommended for best outcomes.[9] Airway stents have been shown to improve quality of life in patients with benign central airway obstruction who are not surgical candidates.[10]

In the literature, zinc supplementation has been used in the treatment rather than the cause of dermal burns; however, there are no robust case reports regarding zinc concentrations on mucosal surfaces.[11] There have been no prior reports of zinc causing airway inflammation, although systemic zinc toxicity is associated with inflammation of the gastric mucosa.

4 Conclusions

We report the first case of a zinc pill aspiration that caused a circumferential chemical airway burn and subsequent bronchial stenosis. In addition, there has been an increase in the self-administration of zinc supplementation for COVID-19 prophylaxis. This case report highlights the previously unknown risks of an unproven treatment considered harmless by members of the community. Given the potential for airway injury, we recommend that zinc tablet aspiration be regarded as similar to iron or potassium tablet aspiration in which bronchoscopy should be performed urgently for foreign body removal.

Author contributions

ETQ, RJL, and FM were involved in the conceptualization of the case report. EQ and JJ were involved in the investigation and data collection. The EQ oversaw the visualization and writing of the original draft. FM supervised the project. EQ, RJL, JJ, and FM reviewed and edited the manuscript.


[1]. Skalny AV, Rink L, Ajsuvakova OP, et al. Zinc and respiratory tract infections: perspectives for COVID-19 (Review). Int J Mol Med 2020;46:17–26.
[2]. Goldbloom A. Broncho-pneumonia following aspiration of zinc stearate powder. Can Med Assoc J 1922;12:491–2.
[3]. Henriques V, Santos DC, Lérias G, Monteiro LC. Iron pill aspiration: cytologic and histologic findings of a potential life-threatening airway injury. a case report and literature review. Diagn Cytopathol 2018;46:532–9.
[4]. Tamburrini M, Jayalakshmi TK, Maskey D, Sharan N, Guiseppe D, Zuccon U. Multivitamin pill aspiration leading to hemorrhagic bronchial necrosis. Respir Med Case Rep 2019;28:100944.
[5]. Chu A, Krishna A, Paul MP, Sexton JF, Mirchia K. Obliterating bronchiolitis: Result of iron pill aspiration. Cureus 2018;10:e2571.
[6]. Shimpi T, Chawla A, Shikhare S. Tell tale of tablets in bronchus. Med J Malaysia 2015;70:36–7.
[7]. Poudel P, Chu A, Mirchia K, Paul M. A patient with a chronic cough: an unexpected case of calcium pill aspiration. J Investig Med High Impact Case Rep 2019;7:1–4.
[8]. Murgu SD, Egressy K, Laxmanan B, Doblare G, Ortiz-Comino R, Hogarth DK. Central airway obstruction: benign strictures, tracheobronchomalacia, and malignancy-related obstruction. Chest 2016;150:426–41.
[9]. Freitag L, Darwiche K. Endoscopic treatment of tracheal stenosis. Thorac Surg Clin 2014;24:27–40.
[10]. Noppen M, Stratakos G, Amjadi K, et al. Stenting allows weaning and extubation in ventilator- or tracheostomy dependency secondary to benign airway disease. Respir Med 2007;101:139–45.
[11]. Lin PH, Sermersheim M, Li H, Lee PHU, Steinberg SM, Ma J. Zinc in wound healing modulation. Nutrients 2017;10:16.

airway stenosis; case report; zinc aspiration

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