luizen

Luizen are parasitic insects that live on humans and feed on blood. In humans the most common forms are hoofdluizen (Pediculus humanus capitis), lichaamsluizen (Pediculus humanus humanus) and schaamluis (Phthirus pubis). They are small, wingless and dorsoventrally flattened, typically about 1–3 mm in length. Adults are pale gray to brown; nits are eggs that attach firmly to hair shafts.

The life cycle starts when a female louse lays eggs (nits) on a host, usually near the scalp or through clothing seams for body lice. Eggs hatch into nymphs after about a week, and nymphs molt into adults after several days. Lice spend their entire life on a host and feed at regular intervals. Off the host, head lice survive only briefly, while body lice can persist longer in clothing or bedding under suitable conditions.

Transmission and symptoms vary by type. Head lice spread mainly through direct head-to-head contact, including in households and schools. Body lice spread via infested clothing and bedding, often in crowded or unhygienic conditions. Pubic lice are typically transmitted through close or sexual contact. Common symptoms include itching and a visible presence of lice or nits on hair or clothing.

Diagnosis is usually by finding live lice or nits on the scalp or other hair-bearing areas. Treatment involves pediculicidal products such as permethrin or pyrethrins, with alternatives like malathion or oral medications in some cases. Non-chemical methods include wet combing and washing of contaminated items (hot water, high heat). Close contacts are typically advised to check and treat if needed to prevent reinfestation. Preventive measures emphasize avoiding shared personal items and regular scalp checks, especially in children.