Pidocchi

Pidocchi are small parasitic insects that infest humans and other mammals. The term usually refers to three forms that affect humans: the head louse (Pediculus humanus capitis), the body louse (Pediculus humanus corporis), and the pubic louse (Pthirus pubis). They feed on blood and spend most of their life on the host, with off-host survival being limited.

Life cycle and biology: The female lays eggs, or nits, cemented to hair shafts near the scalp. Eggs hatch after about 7–10 days into nymphs, which molt three times before becoming adults. Adults live on the host and require regular blood meals; without a host they typically die within a day or two. Lice populations grow when conditions allow close contact and adequate warmth and humidity around the scalp or other hair-bearing areas.

Transmission: Head lice spread mainly through direct head-to-head contact and can also move via shared combs, brushes, hats, or headphones. Body lice are transmitted through contaminated clothing or bedding, while pubic lice spread through sexual contact and shared fabrics.

Symptoms and diagnosis: Itching is common, caused by an allergic reaction to lice saliva. Diagnosis is typically based on finding live lice or eggs on the hair. Nits close to the scalp (often within about 1 cm) support a diagnosis of head lice. Careful combing with a fine-toothed lice comb can aid detection.

Treatment and control: Treatments usually involve pediculicidal products such as permethrin or pyrethrin-based preparations, used according to label instructions, with a second treatment 7–10 days later to kill newly hatched nymphs. Manual removal of nits and lice with a fine comb helps. Washing and drying clothing, bedding, and hair accessories, or sealing items in plastic bags for several days, reduces off-host stages. Some populations show resistance to common pediculicides, requiring alternative products or methods. Prevention focuses on avoiding sharing personal items and reducing close head contact in settings like schools.