This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Scabies and other infestations, Subject name: Dental
'Maculae cerulea' seen in: 
Select and explain. 
A. Pediculosis humanis corporis, B. Pediculosis capitis, C. Pthisis pubis, D. Lupus erythematosus
C: Pthisis pubis
Answer: C: Pthisis pubis 
Explanation: Pthisis pubis (pubic lice) - Seen on pubic hair Initial symptom - Itching Blue grey macules - the "maculae cerulae" Sexually transmitted infection. Diagnosis - Establishing the lice seen as yellow brown specks clinging closely to the base of hair. Rx-shaving of pubic hair Permethrin 2% application Treatment of contact