D1.99 - Allergic contact dermatitis caused by Trofoblastin

Allergic contact dermatitis is an inflammatory skin reaction mediated by delayed-type hypersensitivity (type IV), frequently associated with topical medications applied to damaged skin or following surgical procedures. Trofoblastin®, a topical preparation commonly used to promote wound healing, contains several components with potential sensitizing properties.We report a case of allergic contact dermatitis secondary to the use of Trofoblastin®, confirmed by patch testing.

A 47-year-old woman with a history of allergic rhinoconjunctivitis to pollens and breast carcinoma treated with bilateral skin-sparing mastectomy and immediate reconstruction with tissue expanders.

Postoperatively, Trofoblastin® patches were prescribed to reduce scarring. Four days after application, the patient developed local pruritus and burning sensation, followed by eczematous lesions at the application site with progressive extension across the chest.

She was initially assessed in the Emergency Department and treated with topical corticosteroids, antihistamines, and systemic corticosteroid therapy, achieving complete resolution within 10 days. The patient reported a previous similar but milder episode after prior use of the same product.

Patch testing was performed with:

• TRUE TEST® standard series
• Plastics and adhesives series (Martí Tor)
• The suspected product (Trofoblastin®)

Readings were taken at 48 and 96 hours according to international recommendations.

Patch tests with the standard series and the plastics and adhesives series were negative at both readings.Patch testing with the suspected product showed a positive reaction at 48 hours (+) and a strongly positive reaction at 96 hours (+++).

Definitive withdrawal and avoidance of Trofoblastin® led to complete resolution of symptoms, confirming the clinical relevance of the allergen.

Trofoblastin® may cause allergic contact dermatitis, particularly when applied repeatedly to surgically treated skin.This case highlights the importance of considering topical wound-healing products as potential allergens and underscores the diagnostic value of patch testing with the suspected product.Early identification of the causative agent allows avoidance of re-exposure and prevention of recurrences, thereby optimizing patient management.