-Case Reports-

Ritodrine-induced Pustular Eruptions Distinctly Resembling Impetigo Herpetiformis

Yoshimitsu Kuwabara^1,2, Atsuki Sato^1,2, Hiroko Abe^1,2, Sumino Abe³, Naoki Kawai¹ and Toshiyuki Takeshita²

¹Department of Obstetrics and Gynecology, Tokyo Rinkai Hospital, Tokyo
²Division of Reproductive Medicine, Perinatology and Gynecologic Oncology, Graduate School of Medicine, Nippon Medical School
³Department of Dermatology, Tokyo Rinkai Hospital, Tokyo

A 27-year-old nulligravida woman without a history of dermatosis was hospitalized for threatened preterm labor at 29 weeks' gestation; therefore, continuous infusion of ritodrine hydrochloride was started. At 31 weeks' gestation, erythematous plaques appeared and spread over the body surface; therefore, a topical steroid preparation was applied. At 32 weeks' gestation, the eruptions developed into irregular annular areas of erythema with multiple pustules accompanied by severe itching, and oral prednisolone treatment was started. Bacterial cultures of the pustules were negative, and a crural cutaneous biopsy revealed Kogoj's spongiform pustules. Based on the clinicopathological findings, the most likely diagnosis was impetigo herpetiformis, which causes cutaneous symptoms closely resembling pustular psoriasis in pregnant females without a history of psoriasis. To rule out ritodrine-induced pustular eruptions, the ritodrine infusion was stopped and treatment with an MgSO₄ preparation was started at 33 weeks' 3 days' gestation; however, the uterine contractions could not be suppressed. Because of the patient's highly edematous, severely painful feet, a cesarean section was performed the same day. Within several days of delivery, the eruptions began to resolve, and no recurrence was observed after treatment with oral prednisolone was stopped 31 days after delivery. On the basis of a positive patch test for ritodrine, we diagnosed pustular drug eruptions caused by ritodrine hydrochloride. Although ritodrine-induced pathognomonic cutaneous eruptions are rare, we would like to emphasize that ritodrine can cause drug-induced pustular eruptions distinctly resembling life-threatening impetigo herpetiformis.

J Nippon Med Sch 2011; 78: 329-333

Keywords
pustular eruptions, ritodrine hydrochloride, impetigo herpetiformis

Correspondence to
Yoshimitsu Kuwabara, Department of Obstetrics and Gynecology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
kuwa@nms.ac.jp

Received, March 18, 2011
Accepted, May 18, 2011