RT Book, Section A1 Dooley-Hash, Suzanne A1 Herrman, Nicholas W.C. A2 Knoop, Kevin J. A2 Stack, Lawrence B. A2 Storrow, Alan B. A2 Thurman, R. Jason SR Print(0) ID 1181041442 T1 Pediculosis Pubis T2 The Atlas of Emergency Medicine, 5e YR 2021 FD 2021 PB McGraw-Hill PP New York, NY SN 9781260134940 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1181041442 RD 2024/10/05 AB Pediculosis pubis is caused by the crab louse, Pthirus pubis. The lice are 0.8 to 1.2 mm long and difficult to see. The egg form, the nit, adheres to hair and clothing. Transmission occurs both by sexual contact and less frequently by fomites, such as clothing and towels. Pruritis due to hypersensitivity is typically the primary clinical manifestation. Small blue macules (maculae ceruleae) may also develop secondary to louse anticoagulant saliva injection during feeding. Patients may also notice small blood stains on the undergarments secondary to bleeding from louse bites.