Case Series of Phthirus pubis Infestation in Non-Perineal Regions

Pediculosis has been reported in all countries and socio-economic classes. Due to the small size and translucent nature of their nits, patients with Pthirus pubis may be misdiagnosed. Here, we report three cases of Pthirus pubis infection involving different body sites, including the eyelashes, axillary region and head, respectively. This case series have discussed their clinical features and corresponding responses. A large number of eggs and adult pubic lice were observed under dermoscopic observation, which can be considered an effective tool for diagnosing Pthirus pubis and reducing the misdiagnosis rate.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11–14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

A clinical review and history of pubic lice

The ectoparasite Pthirus pubis (PtP), commonly known as the crab or pubic louse, has plagued primates from prehistoric apes to Homo sapiens. We combed the literature from antiquity to the present day, reviewing the pubic louse's origins, its evolution with mankind, and its presentation and management. MEDLINE and EMBASE provided the greatest yield of literature compared with other databases. Estimates for PtP incidence range from 0.3% to 4.6% and for prevalence around 2% in adults. War, disasters and overcrowding support lice transmission, but modern pubic hair grooming has reduced the incidence of PtP in recent years. PtP, is usually found on pubic hair, but may infest scalp and body hair, eyebrows and eyelashes. Reports suggest the possibility of PtP as a vector for Bartonella spp. and Acinetobacter spp., which require further study. Transmission of PtP is via close contact, so sexual abuse and concomitant sexually transmitted infections should be considered. Symptoms and signs of infestation include pruritus, red papules and rust/brown deposits from feeding or faecal matter. Visualization of live lice confirms the diagnosis. Traditional treatments include hand-picking and combing, but in modern times pediculicidal products may generate faster resolution. Permethrin or pyrethrins are the first-line recommendations. Resistance to pediculicides is common with head lice and is presumed likely with PtP, although data are lacking. Pseudoresistance occurs as a result of poor compliance, incorrect or ineffective dosing, and reinfestation. In true resistance, a different pediculicide class should be used, e.g. second-line agents such as phenothrin, malathion or ivermectin. Lice have existed long before humans and given their adaptability, despite habitat challenges from fashion trends in body hair removal, are likely to continue to survive.

European guideline for the management of pediculosis pubis

Pediculosis pubis is caused by Phthirus pubis. The disease can be sexually transmitted. Patients main complain is of itch in the pubic area. The parasite can be spotted with the naked eye and blue macules can be observed in the pubic area. First line therapy consists of permethrin or pyrethrins with piperonyl butoxide. Second line therapy contains phenothrin, malathion and oral ivermectin. Partner management needs a look-back period of time of 3 months. Pubic lice incidence is increased in populations groups living in crowded spaces with scarce sanitary conditions as in time of war or disaster.

[Main parasitic skin disorders]

Cutaneous parasitic skin diseases are frequent in human pathology. There are few reliable epidemiological data on the prevalence and/or incidence of such diseases. Skin parasites are cosmopolitan but their global distribution is heterogenous; prevalence is especially high in subtropical and tropical countries. They are mainly due to arthropods (insects and mites). Many species of parasites are involved, explaining the diversity of their clinical signs. The most common are caused by ectoparasites such as scabies or pediculosis (head lice, body lice and pubic lice). Clinical signs may be related to the penetration of the parasite under the skin, its development, the inoculation of venom or allergic symptoms. Diagnosis can be easy when clinical signs are pathognomonic (e.g. burrows in the interdigital web spaces in scabies) or sometimes more difficult. Some epidemiological characteristics (diurnal or nocturnal bite, seasonality) and specific clinical presentation (single or multiple bites, linear or grouped lesions) can be a great diagnostic help. Modern non-invasive tools (dermoscopy or confocal microscopy) will play an important role in the future but the eye and experience of the specialist (dermatologist, parasitologist, infectious disease specialist or entomologist) remains for the time the best way to guide or establish a diagnosis. For most skin parasites, therapeutic proposals are rarely based on studies of high level of evidence or randomized trials but more on expert recommendations or personal experience.