The titanium on a pacemaker caused an allergic reaction that led to a woman’s asthma, according to a case study.

The patient: a 58-year-old woman who developed wheezing, chest tightness, and worsening dyspnea on minimal exertion 3 weeks after implantation of a permanent pacemaker. She was a non-smoker with a history of seasonal allergies in childhood.

“On physical examination, the patient had diffuse, bilateral expiratory wheezes on chest auscultation and a raised, erythematous, mildly pruritic and noncrusting rash confined to the skin immediately around the insertion site for her pacemaker,” reported Biplab Saha, MD, of Ozarks Medical Center in West Plains, Missouri, and colleagues in a paper published online in Annals of Internal Medicine.

The patient’s clinical condition was consistent with a diagnosis of asthma despite her baseline FEV₁–FVC ratio not meeting standard measures for airflow obstruction. Asthma was confirmed by evidence of reversible airway obstruction (improvement after bronchodilator administration in FEV₁, FVC, FEV₁–FVC ratio, and FEF_25%–75%).

The woman was treated first with a combination inhaler that included a long-acting β2-agonist and corticosteroid. She later required oral corticosteroids, a leukotriene receptor antagonist, and high-dose antihistamines.

Ultimately, she became steroid-dependent, her asthma remaining poorly controlled, Saha and colleagues reported.

The turning point came when clinicians discovered, in a review of the patient’s medical records, that she had been hypersensitive to costume jewelry as an adolescent. On skin testing for metal allergies, she had positive reactions to titanium, nickel, and mercury, but not gold.

Her titanium-encased pacemaker was therefore replaced with a gold-encased one.

Within 24 hours, her asthma symptoms disappeared. She was able to stop bronchodilators, inhaled corticosteroids, and oral corticosteroids.

“We think that our patient’s asthma was caused by her allergy to the titanium in her pacemaker’s case. The evidence that supports this conclusion includes her history of allergy to costume jewelry, the documentation of her allergy to titanium during skin testing, and the timing of asthma onset and remission with insertion and removal of her titanium-encased pacemaker,” Saha’s group said.

They had found no other reports of a metal implant causing asthma in the literature, the team noted. Others had previously noted rare local reactions caused by metal allergy.