Lice/scabies Symptoms and Causes


General: Lice and scabies are most common among schoolchildren, individuals living in crowded areas, and people living in poverty or unsanitary conditions.
Lice: Humans can get lice after coming into direct contact with lice or their eggs. Lice cannot fly, but individuals may be exposed to them when they touch an infected person or his/her personal belongings, such as bed linens, clothing, stuffed animals, or towels. For instance, head lice are commonly transmitted after sharing pillows, combs/brushes, or hair clips. They can live for up to two days off of the body. Lice can also be spread through sexual contact or after using a toilet seat that was recently used by someone who is infected.
Scabies: Scabies is caused by a burrowing mite, called Sarcoptes scabiei. Scabies is often spread through direct or prolonged skin contact with an infected person or animal (such as a pet dog or cat). It is easily spread through direct contact with sexual partners or family members. It may also be spread after sharing clothes, towels, bedding, or other linens with an infected person.


Lice: A diagnosis can be made after a physical examination. Although lice are very small, they are visible to the human eye. If lice are present, a positive diagnosis is made.
Scabies: During a physical examination, a healthcare provider looks at the skin to see if the characteristic burrows are present. These burrows appear as fine, wavy, and slightly scaly lines. The skin around burrows is red and slightly inflamed. Once a burrow is located, a small skin sample may be taken. This sample is then analyzed under a microscope to see if the mites and/or eggs are present.

signs and symptoms

Lice: Lice typically cause intense itching and small red bumps to develop on affected areas of the skin. The lice may be visible on the skin, body hair, clothing, or other personal items. They are about three millimeters long. Lice eggs, called nits, may also be visible on hair shafts. Nits look similar to dandruff, but they are not easily brushed away.
Symptoms of head lice typically develop on the scalp, ears, nape of the neck, and shoulders. Symptoms of body lice may develop anywhere on the body that has hair. Symptoms of pubic lice typically develop in the pubic area and on the eye lashes.
Scabies: Symptoms of scabies usually develop about four to six weeks after they enter the skin. Scabies causes pimple-like irritations, burrows, or a rash to develop on the skin. The skin on the wrists, elbows, knees, genitals (in men), breasts (in females), shoulder blades, and between the fingers is most likely to be affected. The affected skin is extremely itchy. Itching is most severe at night or after a hot shower or exercise. Individuals may also develop sores and small cuts from scratching the skin.


Individuals with scabies often develop sores and small cuts from scratching affected areas of skin. If bacteria enter the skin through these sores or cuts, an infection may develop.