Summary about Disease
Pediculosis, commonly known as lice infestation, is a parasitic infestation of the skin caused by lice. There are three types of lice that affect humans: head lice (Pediculus humanus capitis), body lice (Pediculus humanus humanus), and pubic lice (Pthirus pubis). Head lice are the most common type, especially among school-aged children. Lice feed on human blood and cause intense itching. While annoying and uncomfortable, lice infestations are generally not dangerous and do not transmit disease.
Symptoms
The most common symptom of pediculosis is intense itching (pruritus) in the affected area. Other symptoms may include:
Tickling feeling of something moving in the hair.
Visible lice on the scalp, body, or pubic area.
Lice eggs (nits) on hair shafts or clothing seams.
Sores on the scalp, neck, shoulders, or groin caused by scratching. These sores can sometimes become infected.
Irritability and difficulty sleeping.
Small, red bumps on the scalp, neck, shoulders, or groin.
Causes
Pediculosis is caused by direct contact with a person who has lice, or by sharing personal items such as:
Hats
Combs and brushes
Clothing (especially hats, scarves, and coats)
Bedding
Towels Head lice spread most commonly through head-to-head (hair-to-hair) contact during play, school, sports activities, or at home. Body lice are often associated with poor hygiene and crowded living conditions. Pubic lice are usually spread through sexual contact.
Medicine Used
Several over-the-counter (OTC) and prescription medications are available to treat pediculosis. Common treatments include:
Permethrin lotion 1% (Nix): An OTC pyrethroid insecticide used for head lice.
Pyrethrins with piperonyl butoxide (RID, others): Another OTC pyrethroid insecticide used for head lice.
Malathion lotion 0.5% (Ovide): A prescription organophosphate insecticide used for head lice.
Benzyl alcohol lotion 5% (Ulesfia): A prescription lotion used for head lice; suffocates the lice.
Ivermectin lotion 0.5% (Sklice): A prescription lotion used for head lice; binds to nerve and muscle cells of the lice.
Spinosad topical suspension 0.9% (Natroba): A prescription topical suspension used for head lice; derived from soil bacteria.
Lindane shampoo 1%: While once common, lindane is generally not recommended due to potential toxicity. It's crucial to follow the instructions carefully for any medication used and to consult a healthcare provider if OTC treatments are ineffective or if you have questions.
Is Communicable
Yes, pediculosis is highly communicable. It spreads easily through direct contact with an infected person or by sharing contaminated items.
Precautions
To prevent the spread of pediculosis:
Avoid head-to-head contact with others, especially during play and sports.
Do not share personal items such as hats, combs, brushes, towels, clothing, and bedding.
Wash clothing, bedding, and towels used by an infected person in hot water and dry on high heat.
Seal non-washable items in a plastic bag for two weeks.
Vacuum carpets, rugs, and upholstered furniture thoroughly.
Inspect family members and close contacts for lice.
Teach children about lice prevention and the importance of not sharing personal items.
How long does an outbreak last?
An outbreak of pediculosis can last for several weeks or even months if not treated effectively. The life cycle of lice is approximately 30 days. Without treatment, the infestation will continue as lice reproduce and lay new eggs. With proper treatment and preventive measures, the outbreak can be resolved within a few weeks.
How is it diagnosed?
Pediculosis is diagnosed by visually identifying live lice or nits on the affected person. A fine-toothed comb can be used to comb through the hair and scalp to look for lice and nits. Nits are often found close to the scalp, attached to the hair shaft. A magnifying glass can be helpful to examine the hair closely. A doctor or school nurse can also diagnose pediculosis.
Timeline of Symptoms
Initial Contact: Lice are transferred to a new host.
1-2 Days: Lice begin feeding. Itching may not be noticeable yet.
3-7 Days: Lice mature and begin laying eggs (nits). Itching may start to become more noticeable.
7-10 Days: Nits hatch into nymphs.
2-3 Weeks: Itching becomes intense. Live lice and nits are easily visible.
Without Treatment: The infestation continues, with lice reproducing and spreading. Secondary skin infections may develop from scratching.
Important Considerations
Not everyone who has lice experiences intense itching. Some people may be asymptomatic.
Nits can be difficult to remove and may require multiple treatments and combing.
Resistance to some OTC treatments is becoming more common. Consult a healthcare provider if OTC treatments are ineffective.
Itching may persist for several days to weeks after successful treatment due to histamine release and skin irritation.
Over-treating can lead to skin irritation and potential resistance of lice to medications. Only treat if live lice are found.
Household pets do not get or spread human lice.