D3.81 - Allergic Contact Dermatitis Induced by Transdermal Estradiol Hormone Replacement Therapy in a Postmenopausal Patient: A Case Report

Background:

Transdermal hormone replacement therapy (HRT) is frequently prescribed for the management of postmenopausal symptoms and is generally considered safe and well-tolerated. Nevertheless, hypersensitivity reactions, particularly allergic contact dermatitis (ACD), may occur and are often underdiagnosed.

Case report:

We present the case of a 56-year-old postmenopausal woman, a former smoker, with no occupational exposure to skin irritants or sensitizers, and a personal history of chronic spontaneous urticaria with angioedema for about 25 years. The patient reported a one-year history of pruritic, eczematous skin lesions, initially localized bilaterally on the inner arms at the sites of transdermal HRT application, which later extended to the axillary regions and lateral thorax. The cutaneous symptoms developed after the initiation of compounded transdermal creams containing estradiol, estriol, progesterone and testosterone. Once dermatitis occurred, the treatment was switched to a transdermal estradiol spray and orally administered micronized progesterone. However, lesions persisted at the application sites. On clinical examination, the patient exhibited intensely pruritic, erythematous, infiltrated, scaly plaques with poorly defined borders, involving the bilateral inner aspects of the arms, as well as the left axillary and left thoracic regions, findings suggestive of contact dermatitis. 

Our goal was to determine if the patient's reaction constituted ACD to the transdermal hormone replacement therapy product. Assessment was performed using repeated open application testing (ROAT) with the patient’s estradiol-based spray, micronized progesterone and the hypoallergenic HRT preparation base. The ROAT was positive for the estradiol product. An eczematous reaction developed 20 hours after the first application and 8 hours after the second, confirming the diagnosis of ACD to transdermal estradiol. ROAT with the other two products remained negative for up to 3 weeks.

Conclusion:

This case highlights estradiol-containing transdermal HRT as a potential trigger of ACD and emphasizes the importance of performing cutaneous tests, particularly repeated open application tests, in establishing the diagnosis. Early recognition of HRT-induced ACD can help guide safe alternative therapeutic strategies for patients.