HomeHealth articlespediculosisPediculosis - Symptoms | Diagnosis | Treatment | Complications

Pediculosis - Symptoms, Diagnosis, Treatment and Complications

Verified dataVerified data

4 min read


Infestation with the human head and body louse, Pediculus humanus, causes pediculosis. They are ectoparasites with only human hosts. Read below to know more.

Written by

Dr. Geethika. B

Medically reviewed by

Dr. Pandian. P

Published At May 31, 2022
Reviewed AtAugust 30, 2022

What Is Pediculosis?

Every year, millions of people worldwide are affected by pediculosis or louse infestation, which has been reported in all countries and socioeconomic classes. Lice are parasitic obligate insects with no free-living stage in their life cycle. They are spread through direct skin-to-skin or fomite-to-skin contact, and symptoms usually do not appear for three to four weeks.

Human parasites include head louse (Pediculus humanus capitis), pubic or crab louse (Pthirus pubis), and body louse (Pediculus humanus). Head lice are the most common lice that cross all socioeconomic barriers, whereas body lice are more common in homeless and displaced populations and should be suspected in these populations when there are signs of scratching, poor hygiene, especially during the colder months.

What Are the Symptoms of Pediculosis?

The symptoms of pediculosis include:

  • Itchy scalp.

  • Having the sensation of something crawling on the scalp.

  • Scratching causes sores and scabs on the scalp.

How Is Pediculosis Diagnosed?

Pediculosis is diagnosed by:

  • By examining the hair near the scalp for lice.

  • Checking the hair near the scalp for nits using fine-toothed lice comb to catch lice and nits starting from the scalp.

  • The nits are dark in color, and the hatched lice are light in color.

  • Adult lice reproduce quickly. Nits on the scalp are evidence of head lice.

It is simple to distinguish between nits and dandruff flakes or other debris in the hair. The majority of debris should be easily removed. Nits will appear to be glued to the hair.

Head lice are spreadable. If one person in the family has them, others may have as well. Checking everyone in the house for lice every few days is a good idea.

How Is Pediculosis Treated?

There are several head lice treatments on the market. The majority of treatments will need to be used twice. After a week to nine days, the second treatment will kill any newly hatched nits.

The following are some of the most common head lice treatments:

  • Head lice treatments are available both over-the-counter (OTC) and by prescription. In over-the-counter head lice treatment, two types of chemicals are commonly used. Pyrethrin is a pesticide derived from the flowers of chrysanthemums. It is safe to use in people over the age of two. If you are allergic to chrysanthemums or ragweed, avoid using pyrethrin. Permethrin is a synthetic pesticide related to pyrethrin. It is safe to use in children aged two months and up.

  • Other chemicals may be included in prescription lice treatments. Aromatic alcohol and benzyl alcohol lotion is used to treat head lice in people aged six months and up. Malathion is a pesticide that contains organophosphates. It is used to treat lice in people over the age of six. It is not advised for pregnant or breastfeeding women. Malathion is a flammable chemical. When using this product, keep it away from open flames and heat sources such as hair dryers.

  • Lindane is a pesticide with an organochlorine structure. It is available as a lotion or a shampoo. Lindane is typically used only as a last resort. It has the potential to cause serious side effects such as seizures and death. Premature babies and people with a history of seizures should not use Lindane. To reduce the risk of side effects, avoid taking more than one medication at a time. Do not take any medication more frequently than prescribed.

  • To remove lice without using pesticides, use a fine-toothed lice comb or a flea comb (available at pet stores). Before combing your hair, apply olive oil to it. This will aid in the adhesion of lice and nits to the comb. Begin combing at the scalp and work your way to the ends of your hair. This should be repeated every two to three days until there are no more signs of lice or nits.

How to Get Rid of the Louse on Household Items?

There is no reason to use pesticides around the house. Lice cannot live off the head for more than a couple of days. In order to eradicate lice completely, the following methods can be used:

  • Clothing and bedding should be washed in hot water (130°F [54°C] or higher) and dried on high heat.

  • Clothes and bedding should be dry-cleaned.

  • Soak combs, hairbrushes, barrettes, and other hair accessories in hot water for 5 to 10 minutes at 130°F (54°C).

  • Floors and upholstered furniture should be vacuumed.

How Can Patients Be Educated?

Noncompliance is a common cause of treatment failure. Patients should be educated on the proper methods for administering medications, including the amount to be used and the duration of treatment. They should also be made aware of the importance of retreatment in seven to ten days. Furthermore, patients and caregivers should be advised that infested bedding, clothing, and towels should be washed in hot water and dried on a high heat setting. Parents and children should be taught not to share headgear such as hats and hair bows. Proper body hygiene, at least weekly clothing changes, and proper clothing laundering are all steps to help prevent re-infestation of body lice after eradication. Sexual partners of patients with pubic lice should also be treated.

What Are the Complications of Pediculosis?

  • Embarrassment in public.

  • Skin breakdown, resulting in secondary bacterial infection (impetigo and pyoderma).

  • Human transmission of trench fever, relapsing fever, and epidemic typhus (body lice only).


In general, louse infestations have a good prognosis. When used correctly, the medications are very effective at eradicating nymphs and mature lice. Treatment failure can be caused by a variety of factors, including a lack of ovicidal activity, failure to remove lice nits, noncompliance, particularly with retreatment in seven to ten days, insufficient application of the pediculicide (that is, duration and amount), failure to treat close contacts, insufficient environmental eradication, and drug resistance to the pediculicide. Some patients with body lice may develop a louse-borne infection, such as trench fever, typhus, or recurrent fever, but this is uncommon.

Frequently Asked Questions


Is Pediculosis a Viral or Bacterial Infection?

Pediculosis is neither of bacterial nor viral origin; it is caused by parasites, namely Pediculus humanus capitis, Pthirus pubis, and Pediculus humanus. These are located over the scalp, pubic hair, and body clothing. It affects millions of individuals worldwide; pediculosis quickly affects young children. They usually spread from one to another through direct contact or shared clothes, combs, and brushes. It results in itching of the scalp, and sores and scabs may arise on scratching.


What Causes Pediculosis?

Pediculosis is a parasitic infestation in the human head and body. It resides on the scalp, pubic area, and over the body. The three species involved in causing pediculosis are as follows:
- Pediculus humanus capitis - Head lice that feed on blood.
- Pediculus humanus - Body lice.
- Phthirus pubis - Pubic lice.
They spread between humans through direct skin contact, and it takes about two to three weeks to notice such infestation.


Is Pediculosis and Scabies the Same?

Pediculosis and scabies are not the same. However, here are the differentiating features of both:
- Scabies is a skin condition caused by Sarcoptes scabiei (mite). They quickly spread through direct contact. It results in itching, and tiny bumps may form on the skin (mainly armpits, between fingers, around the waist, soles of the feet, etc.). The doctor may suggest topical creams or lotions treat it.
- Pediculosis - Parasitic infestation in the head, body, and pubic area occurs due to direct skin contact. It also results in itching after two to three weeks of infestation. The doctor may suggest medicated lotions or shampoos for treatment.


What Are the Complications of Pediculosis?

Pediculosis causes itching of the scalp, sores, and scabs. If left untreated, it may cause the following:
- It results in embarrassment in public.
- The body lice may transmit conditions like trench fever, relapsing fever, and typhus from one person to another.
- The integrity of the skin is lost, leading to bacterial infection.


What Are the Steps Involved in Treating Pediculosis?

The different parasites involved in pediculosis are treated as follows:
- Physical Removal - The head lice are removed by combing from scalp to hair tip.
- Topical Pediculicides - Several topical agents are available to kill the parasites. These agents may kill the lice, but their eggs may remain.
- Therefore repeated treatment with topical agents is essential in achieving a complete cure. It includes Malathion, Lindane, Pyrethroids, etc.
- Oral Medication - Ivermectin is effective in eradicating lice; however, it is still not approved by the FDA (Food and Drug Administration).


Which Drugs Cure Pediculosis?

Repeated topical agents mainly cure pediculosis; several lotions and shampoos are available over the counter to treat them. The doctor may suggest the following medicaments:
- Pyrethroids 1 % is used for three to four weeks and again after one week.
- Lindane 1 % is not used widely due to its side effects.
- Malathion 0.5 % requires a more extended treatment period and has an unusual odor.
- Benzyl alcohol 5 % is available in lotion, which suffocates and kills the lice.
- Finally, topical Ivermectin is effective in a single-use.


What Kind of Infection Is Pediculosis?

Pediculosis is a parasitic infection caused by species like:
- Pediculus humanus capitis.
- Pediculus humanus.
- Phthirus pubis.
These species may live on the scalp, body, and pubic area and spread through direct physical contact. The head lice are 1 to 3 mm long and feed on human blood. Topical medications may aid in treating pediculosis.
Dr. Pandian. P
Dr. Pandian. P

General Surgery


Community Banner Mobile
By subscribing, I agree to iCliniq's Terms & Privacy Policy.

Source Article ArrowMost popular articles

Do you have a question on


Ask a doctor online

*guaranteed answer within 4 hours

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.

This website uses cookies to ensure you get the best experience on our website. iCliniq privacy policy