History of Multiple Allergies and Gradual Onset Running-Related Injuries in Distance Runners: SAFER XXXV.

Objective: To determine if any gradual onset running-related injury (GORRI) was associated with any allergies, multiple allergies (allergies to animals, plants, medication), and allergy medication use.

Design: Cross-sectional descriptive study.

Setting: Two Oceans Marathons (56 km, 21.1 km), South Africa.

Participants: A total of 76 654 race entrants (2012-2015).

Independent variables: The prevalence (%) and prevalence ratios (PR; 95% confidence intervals) for history of (1) any allergies, (2) multiple allergies to broad categories of allergens (animal material, plant material, allergies to medication, and other allergies), and (3) allergy medication use.

Main outcome measures: Using a compulsory online screening questionnaire, the outcome was a history of any GORRIs, and subcategories of GORRIs (muscle, tendon) in the past 12 months and history of GORRIs (and subtypes of GORRIs) were reported.

Results: In 68 258 records with injury and allergy data, the following were significantly associated with reporting any GORRIs: a history of any allergy (PR = 2.2; P < 0.0001), a history of allergies to broad categories of allergens (animal, plant, medication allergy, other) (P < 0.0001), and the use of allergy medication (P < 0.0001). A history of any allergies (PR = 2.4; P < 0.0001), all broad categories of allergies, and allergy medication use were significantly associated with muscle (P < 0.0001) and tendon injuries (P < 0.0001). The risk of reporting a GORRI increased as the number of reported categories of allergies increased (P < 0.0001).

Conclusions: A novel finding was the cumulative risk effect with a history of multiple allergies. Further studies should aim to determine the underlying mechanism relating allergies and GORRIs.