Axillary Apocrine Duct Obstruction in the Context of Long-Term Antiperspirant Use: A Case Report

Axillary osmidrosis (bromhidrosis) is a distressing condition primarily caused by bacterial degradation of apocrine gland secretions, with eccrine sweat creating a moist environment that promotes bacterial proliferation. Aluminium salt-containing antiperspirants are widely used to reduce sweating by transiently obstructing eccrine sweat ducts, thereby indirectly alleviating malodour. However, their long-term effects on apocrine glands remain poorly understood. We report the case of a 34-year-old woman with a 20-year history of axillary osmidrosis who had used an aluminium chloride-containing antiperspirant daily for many years. She had been instructed to discontinue all antiperspirants 72 hours before surgery but reapplied the product approximately 24 hours preoperatively. During planned minor-incision excision of the apocrine glands, multiple white, well-circumscribed spherical masses were unexpectedly identified within the superficial subcutaneous tissue of both axillae and were readily dissected from the surrounding connective tissue. Histopathological examination demonstrated apocrine gland hyperplasia with focal ductal ectasia and retained secretory material, suggestive of chronic ductal obstruction. The patient recovered uneventfully, with marked improvement in axillary malodour. To our knowledge, this is the first report to describe such intraoperative and histopathological findings in a long-term user of an aluminium-containing antiperspirant. However, aluminium-specific staining was not performed and the presence of aluminium in the excised tissue could therefore not be confirmed; the observed association with antiperspirant use remains temporal rather than causal. Clinicians should remain aware of potential structural alterations of the apocrine glands in long-term users and consider discontinuing antiperspirants before axillary surgery.