A 38-year-old Hispanic woman presented with a widespread papulosquamous eruption with accentuation on the palms and soles (Fig 1, A). Travel history was remarkable for a recent trip to her native country (Dominican Republic). Her 13-year-old son, who accompanied her on the trip, developed a similar rash after their return (Fig 1, B). In addition, the patient noted that her boyfriend, whom she was visiting in the Dominican Republic, had a rash when she arrived. The rapid plasma reagin (RPR) test produced negative findings whereas the skin biopsy specimen from the patient’s foot showed a psoriasiform lichenoid dermatitis teeming with spirochetes highlighted by a Steiner stain. After discussion with the laboratory about the RPR results, serial dilutions proved positive (prozone effect). At follow-up 4 days later, the son was evaluated for his rash. As expected, the patient’s fluorescent treponemal antibody absorption (FTA-ABS) test result was positive, but the son’s test finding was only minimally reactive.
