Phthirus pubis (Anoplura: Phthiridae) infestation of the palpebral margin and scalp hair in an infant

This paper reports a rare case of Phthirus pubis infestation of the palpebral margin and scalp hair in an 8-month-old infant. Under the microscope, the lice were observed to have a short and wide, crab-like shape, and were identified as P. pubis. Further molecular identification based on mtDNA cox 1 showed that the sequence of lice obtained were 99.70% identical to that of P. pubis , and only 74.73% similarity to that of Pediculus humanus capitis in GenBank. Therefore, the lice infesting the infant was determined to be P. pubis rather than Ped. h. capitis . The patient was cured by mechanical removal of the lice and treatment with ofloxacin eye drops. This report suggested that while the diagnosis and treatment for phthiriasis is not difficult, the case was rare in the clinic and could be easily ignored, resulting in it going undiagnosed or misdiagnosed, leading to delayed treatment.