Background

Phthiriasis palpebrarum, also known as ciliary phthiriasis or phthiriasis ciliaris, is an ectoparasitosis of the eyelash brought on by a crab louse or pubic louse infestation (Pthirus pubis, often spelled as Phthirus pubis). A hematophagous arthropod belonging to the order Anoploure and class Insecta is called Phthiriasis palpebrarum.

It belongs to the genus Phthirus and the family Pediculidae. It is an uncommon condition that is sometimes mistaken for blepharitis. It is not as uncommon as previously reported and is more common in lower socioeconomic groups. Since it clinically resembles anterior blepharitis, it is likely that a significant percentage of cases are being overlooked.

Furthermore, it’s simple to overlook the nits and adult lice hiding in the eyelash hairs. Clinical signs such as compulsive scratching, lid hyperemia, & excoriated skin can be present. Phthiriasis palpebrum is a sign of poor hygiene, crowding, poverty, & lower socioeconomic status in a certain area. It is a serious infection that authorities should consider when establishing treatment protocols.

Epidemiology

According to estimates, 1 – 2% of the world’s population is affected by pubic lice. Phthiriasis palpebrarum affects an unknown number of people. According to certain research, the prevalence of phthiriasis pubis can range from 2 percent to over 10 percent.

This prevalence is likely understated, though, because first-line doctors regularly treat non-declared cases. Due to social stigmas and restrictions, cases in the Indian population usually go unreported.

Anatomy

Pathophysiology

Itching is thought to be brought on by cutaneous hypersensitivity to the saliva of the louse. The scalp, trunk, axillary region, groin, thighs, eyebrows, & eyelashes can all be infected with adolescent pubic lice. Rarely do eyelashes get involved. If it does exist, the main cause is crab louse; head louse is relatively infrequent. Body louse association with eyelashes is not observed.

The pubic louse can swiftly infect hair by itself and spread from vaginal regions to lashes or other locations. Adult lice, on the other hand, are spread by contact with hands, unclean clothing, linen, and towels. The most common infection in children’s eyelashes is a very remote potential of sexual assault, which needs to be ruled out.

Etiology

Pthirus pubis, an obligatory human parasite and hematophagous arthropod that causes phthiriasis palpebrarum, is also known as Phthirus pubis. It is an insect from the genus Pthirus and the family Pthiridae. Shorter than body lice & head lice (Pediculus humanus capitis), adults can reach a length of 2 mm (Pediculus humanus corporis). In comparison to head & body lice, male parasites are smaller than female parasites.

The parasite Pthirus pubis (ciliary phthiriasis) has a spherical, crab-like structure & thick second and third sets of legs with big claws that allow it to adhere to the hair. It primarily infests pubic hair (inducing phthiriasis pubis). It could, however, spread to other hairy regions, including the beard, eyebrows, eyelashes, axillary area, thighs, belly, & chest. Blood is consumed by Pthirus pubis approximately five times every day.

It is only capable of surviving for between 24 and 48 hours without its host body. An average of three nits are laid by a female louse each day, and they hatch 7–10 days ago. Pthirus pubis infection generally happens during sexual activity or even during encounters between an infected child and their parent. Pthirus pubis can be manually transferred to eyelashes from infected body hair or through sex.

Some authors dispute the less common indirect spread of nits through contaminated towels or garments. Rarely can phthiriasis palpebrarum be mistaken for blepharoconjunctivitis. A 48-year-old female was the first person to be diagnosed with Phthirus pubis and Demodex of the eyelids, according to Huo et al. A case of uniocular phthiriasis palpebrarum infection in a young child undergoing occlusion therapy for amblyopia was described by Biler et al.

Genetics

Prognostic Factors

In most cases, the prognosis for phthiriasis palpebrarum is favorable. Neglected episodes of the parasite’s chronic infection can lead to blepharitis, meibomian gland malfunction, & dry eyes, all of which call for specialized care.

Clinical History

Clinical History

The primary symptom of phthiriasis palpebrarum is itchiness of the eyelids. Diffuse inflammatory conditions may result from continuous scratching, wiping the eyelashes, & pruritis. Less frequently reported symptoms to include redness, gritty sensation, enlarged eyes, hyperemia, watering, reddish-brown crusts, burning sensation, white discharge, discomfort, and irritation.

Since doctors rarely meet phthiriasis palpebrarum due to the parasite’s tiny size, translucent nature, & nits, which make them hardly visible, this ailment may not be correctly recognized. Before phthiriasis palpebrarum is formally diagnosed, eye symptoms may progress for months. An accompanying phthiriasis pubis is indicated by a localized and generalized itching of body parts with hair. Lid abscesses have occasionally been recorded.

Physical Examination

Physical examination

Slit lamp examination reveals translucent nits, which resemble oval formations and are found along the lash line. Lice resemble moving translucent structures. The quantity of lice varies (1 louse to dozens). Similar results may be obtained through dermatoscopy. As a result of the parasite’s blood intake, it is common to see palpebral edema and erythema, hyperemia blepharoconjunctival, hematic crusts, & petechial macules of the skin of the lids.

Small brown granules that resemble feces are visible. Phthiriasis palpebrarum typically involves both eyes, with the involvement of just one eye being less frequent. Upper eyelids appear to be affected the most commonly. Usually, there is no change in eyesight. Pre-auricular lymphadenopathy could be present, particularly in cases of parasite bites or secondary severe infection of ocular excoriations.

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Differential Diagnosis

Marginal keratitis

Demodicosis

Atopic dermatitis

Staphylococcal blepharitis

Rosacea blepharitis

Eyelid eczema

Hordeolum

Dry eye disease

Chalazion

Follicular conjunctivitis

Allergic conjunctivitis

Viral conjunctivitis

Bacterial conjunctivitis

Blepharoconjunctivitis

Seborrheic blepharitis

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Mechanical Removal

A radical procedure is to cut your eyelashes. In uncooperative individuals, like children, physically removing lice & nits from the lashes may be challenging. A cost-effective adjuvant treatment that makes physical removal easier is the use of botulinum toxin A at a concentration of 2.5 units / 0.1 ml given with a swab stick on the lashes. This treatment paralyzes the lice, preventing them from attaching to the eyelashes.

Topical Drugs

Phthiriasis palpebrarum can be treated with a variety of topical medications. Liquid vaseline, topical botulinum toxin, 20 percent fluorescein, 0.3 percent tobramycin ocular ointment, 0.5 percent moxifloxacin ocular ointment, yellow 1 percent mercuric oxide ocular ointment (earlier publications), parasympathomimetic drugs (physostigmine ointment, 4 percent pilocarpine gels), & liquid petrolatum ointment have been reported to be efficient on lice and nits. 1 percent permethrin, topical 0.5percent to 1 percent shampoo or malathion, 0.2 percent phenothrin, 50 percent tea tree oil, & lindane (often incorrectly stated as gamma-benzene hexachloride) are just a few examples of the topical antiparasitic medications that may be provided.

Argon Laser Treatments & Cryotherapy

An option for manual removal and topical therapy may be parasite killing. Some writers claimed that liquid nitrogen cryotherapy carried out under a slit light was effective. Several authors have suggested argon laser therapy has been suggested by several authors as a successful therapy for phthiriasis palpebrarum. Lice & nits could be destroyed in a single session employing a 200-micron beam with a range of 0.1 seconds and then a strength of 0.2 W. Although this technology requires tight protective eyewear, it might not be widely accessible.

Use of Ivermectin

Ivermectin can be used orally as a single dosage treatment, but because of the drug’s 16-hour half-life, a second dose may be required seven to ten days later to manage freshly hatched nits. Ivermectin taken orally should not be administered to children under the age of five or who weigh less than 15 kilograms. Ivermectin has unfavorable side effects in pregnant and nursing women because it can penetrate the blood-brain barrier. Ivermectin inhibits the transmission of electrical impulses by the nerve’s synaptic terminals. The parasite is killed when its actions on the neurotransmitters GABA (gamma-aminobutyric acid) or glutamate paralyze it.

Typical Hygiene Procedures

Shaving or applying an antiparasitic dermal solution must be used to treat the accompanying body hair infection. To get rid of both lice & nits, wash clothing, blankets, pillowcases, & towels at 50 C for 30 minutes, and then heat dry for up to 10 minutes. The presence of phthiriasis pubis & phthiriasis palpebrarum should be checked in all sexual partners & relatives, and if present, the condition must be treated. Such precautions have been shown to be effective in preventing recontamination.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Future Trends

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK459226/