The New England Journal of MedicineImages in Clinical Medicine: Pubic Lice

A Case Study Highlighting Sexual Transmission and Effective Management Strategies

A 59-year-old male patient presented with severe itching in the pubic region, leading to a diagnosis of pubic lice infestation, a condition primarily transmitted through sexual contact. This case study not only reinforces the importance of prompt and accurate diagnosis but also illuminates the efficacy of treatment and necessary preventive measures. The patient’s history and examination provide key insights into the lifecycle and management of Phthirus pubis, contributing to a broader understanding of sexually transmitted parasites.

Key Points:

• Patient Presentation: A 59-year-old man reported severe pubic itching for four weeks, with a history of sexual contact with a new partner 16 weeks prior.
• Physical Examination Findings: Presence of brown nits and mobile, crab-shaped lice on pubic hair shafts and bases, confirmed by dermoscopic examination.
• Dermoscopic Observations: Identification of nits with a cap or operculum and live lice actively ingesting blood.
• Diagnosis: Confirmed case of pubic lice (Phthirus pubis) infestation, with no lice found on other body parts.
• Lifecycle of Phthirus pubis: Includes stages as nit (egg), nymph, and adult louse, with an adult louse dying within 48 hours without blood feeding.
• Treatment Administered: Topical application of lindane, the only available lice-killing medication in the locality.
• Additional Testing: Negative results for syphilis, HIV, and gonorrhea.
• Preventive Measures Advised: Washing clothing and bedsheets in hot water and abstaining from sexual contact until treatment success.
• Treatment Outcome: Significant reduction in itching one week post-treatment completion.

About 3 million people in the US get pubic lice every year.

More on Parasitic Diseases