[Proxy lymphomatoid contact dermatitis]

Lymphomatoid contact dermatitis is a delayed hypersensitivity reaction predominantly featuring T-cell infiltration. We report a case mainly involving B-cell infiltration associated with eczema and resulting from an indirect proxy contact with an allergen in a conjugal setting.

A 32-year-old man had an infiltrated cutaneous lesion on the interior aspect of the left arm with eczematous lesions of the waist and the anterior aspect of the left arm which were present for 6 months. All of these lesions were unresponsive to strong local steroids. Biopsy of the infiltrated lesion showed a dense lymphoid dermal infiltration chiefly comprising B cells. Histological examination of a waist lesion revealed chronic eczema. Patch testing was performed with the ECDRG test battery. A PPD (paraphenylenediamine) patch test was the only examination yielding a positive result. Detailed questioning revealed use of a hair dye by the patient's spouse and withdrawal of the allergen resulted in complete remission of the two types of lesion.

This case highlights the ability of a single allergen to induce different lymphoid phenotypes. It also underscores the value of detailed questioning in allergology.