Exercise-Induced Anaphylaxis in an Air Force Aviator Taking a HMG-CoA Reductase Inhibitor: A Case Report and Review of the Presentation, Diagnoses, and Treatment.

BACKGROUND

A 46-year-old healthy male Air Force pilot presented to the emergency department (ED) experiencing symptoms of exercise-induced anaphylaxis (EIAn), during a vigorous outdoor run. The patient recovered in the ED and was seen, subsequently, by a civilian allergist; eventually a diagnosis consistent with EIAn was made. EIAn is a rare but potentially life-threatening syndrome believed to involve IgE mediated release of histamine and other immunoactive compounds, during or after exercise. The diagnosis is determined by a strong clinical suspicion along with careful exclusion of other potential diagnoses. Interestingly, this particular patient was also found to have a possible correlation between the introduction of 3-hydroxy-3-methylglutaryl-coenzyme A, for hyperlipidemia, shortly before his first episode of EIAn, and remission of the condition since discontinuing the statin medication.

METHODS

A detailed review of the clinical notes, ED presentation, and all subspecialty consultation notes were include in the compilation of this case report, in conjunction with a careful review of all current literature pertaining to drug exacerbated, exercise-induced EIAn. The review of literature was also conducted to review potential mechanisms of this particular hypersensitivity reaction, and to give a thorough discussion of the history and presentation of this disorder.

RESULTS

The patient described in this case was successfully treated over a 2-year period, with exercise modifications and a daily second generation antihistamine. Nearly a year after his initial diagnoses, in an acute visit to the flight medicine clinic for muscle soreness and elevated creatine kinase isoenzymes, the patient's medication profile was reviewed and his statin medication was discontinued. The clinical notes revealed that the statin was started a few months before his first onset of EIAn, and following its discontinuation, the patient has been asymptomatic for over a year, exercising regularly, and completed a successful forward deployment to an austere desert environment.

DISCUSSION

To our knowledge, this is the first reported case of possible statin exacerbated, EIAn. Data concerning the incidence of drug-induced hypersensitivity to statins are limited as is any discussion on prevalence of EIAn in adult populations. There have been, however, case reports documenting statin immunological effects on serum IgE levels, which may offer a potential mechanism of statin-exacerbated EIAn. However, the role of IgE antibodies in drug-induced anaphylactic reactions remains unclear. In this patient's case, there was no measure of statin-specific immune reactivity performed; however, the timing of statin initiation of monotherapy in relation to presentation of EIAn strongly supports the diagnosis of statin-exacerbated EIAn. Although the mechanisms involving statin-induced EIAn remain elusive, this case report illustrates the need for military providers to recognize this condition and cofactors that may contribute to its genesis. Moreover, this case also illustrates the need for increased research and surveillance of this condition in civilian and military populations.