What are pubic lice called? - briefly
Pubic lice are scientifically named Pthirus pubis and are colloquially referred to as “crabs.” They are parasitic insects that infest the coarse hair of the genital area.
What are pubic lice called? - in detail
Pubic lice, scientifically designated Pthirus pubis, are also referred to as crab lice because of their short, broad body and crab‑like claws that cling to coarse hair. They belong to the order Phthiraptera, family Pthiridae, and are obligate ectoparasites of humans.
Morphology
- Size: 1–2 mm in length.
- Body: flattened, oval, with a hard exoskeleton.
- Legs: three pairs, the front pair enlarged for grasping hair shafts.
Life cycle
- Egg (nit) attachment to hair shaft, incubates 6–10 days.
- Nymphal stages (three molts) lasting 5–7 days each.
- Adult stage, lifespan up to 30 days on the host; can survive up to 2 days off‑host.
Transmission
- Direct skin‑to‑skin contact, most commonly during sexual activity.
- Indirect transfer via contaminated clothing, bedding, or towels is rare but possible.
Clinical presentation
- Intense itching in the genital area, sometimes extending to the abdomen, thighs, or perianal region.
- Visible live insects or dark, oval eggs attached to pubic hair.
- Small bluish macules (punctate hemorrhages) where lice bite.
Diagnosis
- Visual inspection of hair for adult lice and nits.
- Dermatoscopy can enhance detection, especially in early infestations.
Management
- Topical pediculicides (e.g., 1% permethrin lotion) applied to affected hair, left for the recommended duration, then rinsed.
- Second application after 7–10 days to eradicate newly hatched lice.
- Manual removal of nits with a fine-tooth comb may reduce reinfestation.
- Oral ivermectin, 200 µg/kg, single dose, used when topical agents are contraindicated or ineffective.
Prevention
- Avoid sharing personal items that contact pubic hair.
- Wash clothing, bedding, and towels in hot water (≥ 60 °C) and dry on high heat.
- Treat sexual partners simultaneously to prevent re‑infestation.
Understanding the taxonomy, morphology, and life cycle of Pthirus pubis informs accurate identification, effective treatment, and appropriate preventive measures.