Lymphomatoid contact dermatitis caused by nickel.

Lymphomatoid contact dermatitis is a rarely reported entity consisting of allergic contact dermatitis that resembles mycosis fungoides pathologically. Although the histopathology has been previously described, there have been no attempts to reproduce the dermatitis for pathologic evaluation. A 68-year-old woman presented with a papular rash on her neck after exposure to a nickel-containing necklace. A biopsy specimen was suspicious for mycosis fungoides. However, the dermatitis responded quickly to topical steroids and avoidance of the necklace. A patch test to nickel was positive, and a biopsy specimen from the patch test site had no findings of mycosis fungoides. Although we were able to reproduce the contact dermatitis at a distant site, the disease was dissimilar. Lymphomatoid contact dermatitis has an excellent prognosis and resolves completely simply by avoiding the offending agent.