Colophony Detection in Military Footwear and Its Implications for the Management of Allergic Contact Dermatitis in Soldiers.

INTRODUCTION: Allergic contact dermatitis (ACD) of the feet is an occupational problem in military populations and may affect soldiers' ability to meet occupational and operational requirements, particularly in roles requiring prolonged use of standard military footwear. Colophony (rosin) is a recognized contact allergen implicated in shoe dermatitis. In the Israel Defense Forces (IDF), standard-issue military boots are considered colophony-free based on manufacturer declarations.

MATERIALS AND METHODS: This investigation was conducted as a quality-improvement initiative combined with policy implementation within the IDF Medical Corps. Following a recurring clinical pattern of suspected footwear-related ACD in which colophony sensitization was identified during specialist evaluation, laboratory analyses were performed in June and August 2025 at an independent analytical laboratory. The initial assessment included 2 commonly issued boot pairs. The expanded assessment included 9 boot pairs representing footwear types issued by the IDF at the time of testing and multiple manufacturers. Four samples were obtained from each pair from internal regions selected to correspond to the recurring clinical distribution of dermatitis. Samples underwent solvent extraction, methylation, and quantitative gas chromatographic analysis according to Methods for the Determination of Hazardous Substances (MDHS) 83/3. Before formal footwear testing, a preliminary feasibility assessment was performed to confirm extraction of colophony from the footwear matrix; a full footwear-specific validation was not performed. Individual-level clinical data and case counts were not systematically collected.

RESULTS: In the initial laboratory assessment, 8 samples were analyzed from 2 boot pairs. Five contained quantifiable colophony concentrations above the limit of quantification (3.0 µg/g), ranging from 4.73 to 12.94 µg/g. One additional sample contained 2.1 µg/g, above the limit of detection but below the limit of quantification, and 2 samples were below the limit of detection (<1 µg/g). In the expanded assessment, all 36 samples from 9 boot pairs were below the limit of detection (<1 µg/g). Clinically, a recurring pattern of dermatitis associated with standard military footwear was observed, including improvement during footwear exemption and recurrence following return to standard boots. Colophony sensitization was identified on patch testing during specialist evaluation. These findings contributed to the development of a structured, stepwise footwear replacement protocol.

CONCLUSIONS: Colophony was detected in selected military footwear samples, although this finding was not reproduced in the expanded assessment. In soldiers with suspected footwear-related ACD, laboratory findings should be interpreted in conjunction with clinical history and patch test results. A structured, stepwise management protocol can provide individualized care while supporting continued service in footwear-dependent roles and maintaining operational standards.