How does pediculosis manifest? - briefly
Pediculosis is characterized by intense itching and the presence of live lice or attached eggs (nits) on hair shafts, often accompanied by redness, scalp irritation, and occasional secondary bacterial infection.
How does pediculosis manifest? - in detail
Pediculosis presents with a characteristic set of cutaneous and systemic signs that vary according to the species involved and the site of infestation. The most common form, head‑lice infestation, produces the following clinical features:
- Pruritus that intensifies several hours after a night’s sleep, caused by the saliva injected during feeding.
- Presence of live nits firmly attached to hair shafts within 1 mm of the scalp; nits appear as oval, translucent or brownish structures.
- Adult lice, 2–4 mm long, brown‑gray, mobile on the scalp; they may be observed moving rapidly when the hair is examined under magnification.
- Small erythematous papules or excoriations scattered over the scalp, neck, and behind the ears, reflecting repeated bites.
- Secondary bacterial infection of scratched lesions, potentially leading to impetigo or cellulitis.
Body‑lice infestation (Pediculus corporis) yields similar itching but with additional findings:
- Small, red papules or vesicles at the site of attachment, often on the torso, arms, or thighs.
- Visible lice and nits on clothing fibers; removal of infested garments eliminates the source.
- Possible dermatitis from prolonged exposure to louse saliva and feces.
Pubic‑lice infestation (Pthirus pubis) displays distinct manifestations:
- Intense pruritus in the pubic region, perianal area, or other coarse‑hair sites (axillae, chest, facial hair).
- Bluish‑gray macules or excoriations where lice have fed.
- Live lice or nits attached to the base of hair shafts; nits may be visible as white or brown specks.
- Occasionally, erythematous papules on the surrounding skin due to allergic reaction to saliva.
In all forms, the latency period between initial contact and symptom onset ranges from 3 to 10 days, reflecting the time required for lice to mature and commence feeding. Persistent scratching can exacerbate skin inflammation and increase the risk of secondary infection. Diagnosis relies on direct visualization of viable lice or attached nits; laboratory confirmation is rarely needed. Effective management combines topical pediculicides, thorough combing of hair or removal of infested clothing, and hygiene measures to prevent reinfestation.