bubble_chart Overview

Pediculosis is a skin disease caused by lice and occurs worldwide. Pubic lice are a type of pediculosis that can be transmitted through sexual contact, often affecting both partners, with women being more commonly affected. In recent years, it has been prevalent in the United States and Western Europe.

bubble_chart Epidemiology

In recent years, this disease has been prevalent in the United States and Western Europe, primarily transmitted through sexual contact, especially among unmarried young people. The incidence is higher in women than in men, with the age range being 15 to 19.

In rural areas of China, particularly in the colder northern regions, it is more common, but typically involves body lice and head lice, with occasional cases of pubic lice. The main cause of the epidemic is poor sanitary conditions. However, with the resurgence of sexually transmitted diseases in recent years, the transmission of pubic lice cannot exclude sexual contact as a means of pestilence.

bubble_chart Etiology

Lice can be divided into three types based on their morphology and the location of Chinese Taxillus Herb: head louse, body louse or clothes louse, and pubic louse. They inhabit human hair, underwear, and pubic hair respectively. All feed on human blood and release toxic saliva during feeding. Both their bites and venom can cause cutaneous pruritus dermatitis. Clothes lice can transmit pestilence, relapsing fever, epidemic macula and papule cold-damage disease, and trench fever. Pubic lice generally do not spread pestilence, but isolated reports suggest they may transmit pestilence macula and papule cold-damage disease under certain circumstances.

Pubic lice are shorter and broader than head and body lice. Female pubic lice measure 1.5×2.0 mm, while males measure 0.8×1.2 mm. They have three pairs of legs, with the front pair being slender and the other two pairs having hook-like claws. Their thorax and abdomen are fused without clear demarcation, and their abdomen is short and wide, somewhat resembling a crab. They typically cling tightly to pubic and anal hair with their large claws, and spreading to armpit hair, eyebrows, or eyelashes is uncommon.

They usually grasp nearby hair to feed with their mouthparts but may also crawl on the skin, appearing as small grayish-yellow particles. They are generally confined to pubic hair or the lower abdomen. Their eggs are attached diagonally to pubic hair, appearing as rust-colored or pale red particles, sometimes resembling dotted blood scabs, making them easily distinguishable from the white eggs of head lice.

Pubic lice are photophobic, preferring dark areas, and are active both day and night. They remain motionless when temperatures are too high or too low. After mating, adult females become fertilized within 24 hours and begin laying eggs. Pubic lice produce fewer and smaller eggs, laying about three per day until 24–48 hours before death, totaling around 50 eggs in their lifetime. Adult lice live for about 30 days and die within 24 hours of leaving the host. Lice undergo incomplete metamorphosis, with their life cycle consisting of eggs, nymphs, and adult late stage [third stage], all completed on the host. Females secrete a glue-like substance when laying eggs, ensuring they firmly adhere to hair or fabric fibers.

bubble_chart Clinical Manifestations

Pubic lice inhabit the pubic and perineal hair. They exhibit some mobility, causing cutaneous pruritus in the pubic area and nearby regions. Scratching leads to excoriations, blood crusts, or secondary infections such as impetigo and folliculitis. Occasionally, soybean-sized or fingernail-sized Dyers Woad spots—small grayish pigmented spots, generally no larger than 1 cm in diameter—appear at the bite sites. These spots may be an allergic reaction to the lice's saliva or, as some suggest, due to hemoglobin discoloration caused by the lice's saliva entering the bloodstream during feeding. Minor bleeding at the bite site can turn the area into a bluish spot. These bluish spots may persist for several days even after the lice are eradicated. The lice themselves can be found at the hair follicle openings, while rust-colored nits are visible on the hair shafts.

bubble_chart Auxiliary Examination

Specimen collection: Use scissors to cut the pubic hair with pubic lice and eggs.

Specimen fixation: Fix with one of the following fixatives: 70% alcohol or 5-10% formalin solution. Place the fixed specimen on a slide, add a drop of 10% potassium hydroxide solution, heat slightly over an alcohol lamp, and observe under a microscope.

Results: Pubic lice are crab-shaped, with 3 pairs of legs—the front legs are smaller, while the middle and hind legs are large and have thick claws for grasping pubic hair. The eggs are rust-colored or light red.

bubble_chart Diagnosis

The patient can make the diagnosis themselves by checking for worms or lice eggs in Chinese Taxillus Herb. Observe their characteristics under a microscope.

bubble_chart Treatment Measures

It's best to shave off pubic hair, boil or iron underwear, and use 1% malathion powder externally. Chinese medicinals include 25-50% stemona root tincture, 1% gamma-666 cream, or 25% benzyl benzoate emulsion, all of which can kill lice. Alternatively, you can use Miehai Ling spray locally and wash it off after 3 minutes.