Department of Rheumatology, AP-HP, Saint-Antoine Hospital, Pierre-et-Marie-Curie University, 184, rue du Faubourg-Saint-Antoine, 75012 Paris, France.
Joint Bone Spine. 2011 Jul;78(4):402-4. doi: 10.1016/j.jbspin.2011.02.008. Epub 2011 Mar 26.
Crusted Norwegian scabies is an extremely rare hyperkeratotic variant of scabies infestation. We report herein a case of crusted scabies in a woman with severe rheumatoid arthritis (RA) treated by tocilizumab (TCZ), a monoclonal antibody blocking the interleukin-6 receptor.
An 80-year-old female with severe RA developed erythroderma followed by hyperkeratosis, widespread scaling over the trunk, arms, hands and limbs, and crusted lesions on her scalp. She was on TCZ (8 mg/kg per month) with prednisone (20 mg/d). Several hypotheses were evoked (i.e., vasculitis, psoriasis or paraneoplasic syndrome) but a microscopic examination of the skin surprisingly demonstrated numerous scabies mites and eggs leading to the diagnosis of crusted (Norwegian) scabies. After repeated use of ivermectin and application of topical piperonyl butoxide cream, scabies disappeared. However, there had been outbreak of scabies among two individuals in the staff and two patients. TCZ was stopped after four infusions because of a severe infectious pneumonia and failure.
Crusted scabies should be evoked in case of pruritus or erythroderma occurring under TCZ therapy and it may be explained by the interleukin-6 blockade.
结痂性挪威疥疮是疥疮感染的一种极罕见的角化过度变异型。我们在此报告一例接受托珠单抗（TCZ）治疗的严重类风湿关节炎（RA）女性患者的结痂性疥疮病例，TCZ 是一种阻断白细胞介素-6 受体的单克隆抗体。
一名 80 岁女性患有严重 RA，出现红皮病，随后出现角化过度、躯干、手臂、手部和四肢广泛鳞屑、头皮结痂性病变。她正在接受 TCZ（每月 8mg/kg）和泼尼松（20mg/d）治疗。提出了几种假说（即血管炎、银屑病或副肿瘤综合征），但皮肤显微镜检查令人惊讶地显示出大量疥螨和卵，从而确诊为结痂性（挪威）疥疮。在反复使用伊维菌素和局部涂抹胡椒基丁醚乳膏后，疥疮消失了。然而，在工作人员中出现了两例和两名患者中爆发了疥疮。由于严重的传染性肺炎和治疗失败，在输注四次后停止了 TCZ 治疗。
在 TCZ 治疗期间出现瘙痒或红皮病时应考虑结痂性疥疮，这可能是由于白细胞介素-6 阻断所致。
