Why the onset of an itchy eruption on her neck?

This 56-year-old female presented with a sudden onset of an itchy eruption on her neck of two days duration. She denies any exposure history.

What would you suspect?

A.Photodrug reaction.

B.Contact dermatitis.

C.Herpes zoster.

D.Cutaneous lupus.

E.Phytophotodermatitis.

(Answer and discussion on next page)

ANSWER—Contact dermatitis

Upon further questioning, the patient revealed that she had used a new perfume. The citrus scent suggested the presence of oil of bergamot, which can result in a phototoxic reaction called berloque dermatitis. Bergapten in the oil contains a 5-methoxypsoralen—a furocoumarin found in limes which results in a phototoxic reaction when exposed to light. ■

David L. Kaplan, MD, is clinical assistant professor of dermatology at the University of Missouri, Kansas, City School of Medicine and at the
University of Kansas School of Medicine. He practices adult and pediatric dermatology in Overland Park, KS.