AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Periorbital infections comprise a group of infections that can be broadly classified into two distinct groups. One group consists of infections of the dermis and associated tissues around the eyes. The other group consists of infections of the lacrimal system.

Infections of the superficial skin around the eyes are called periorbital or preseptal cellulitis. These are limited to the area anterior to the orbital septum. The orbital septum is a fibrous sheet that extends from the periosteum of the orbit as the arcus marginalis and lies just deep to the orbicularis oculi muscle. In the upper lids, the septum fuses with the levator aponeurosis. In the lower lids, the septum fuses with the orbital retractor. The orbital septum acts as a physical barrier to the spread of infection.

Infections of the lacrimal system are classified based on the location of the infection. The lacrimal gland is located in the lateral upper lid margin. It produces about 10 mL of secretions per day. In the process of blinking, the eyes close from lateral edge to the medial edge pushing the tear film across the surface of the eye. Most of the tear volume is lost by evaporation. A small portion is drained from the lacrimal lake located at the inner canthus through the puncta and into the canaliculi. Tears then flow into the common canaliculus and lacrimal sac. The lacrimal duct, which lies within the bone, connects the lacrimal sac with the eventual site of egress, the inferior meatus of the nose.

Blepharitis is an inflammation of the lid margins. Anterior blepharitis affects the area of the lid where the eyelashes attach. Posterior blepharitis affects the inner portion of the eyelid margin that is in contact with the eye.

Dacryoadenitis is inflammation of the lacrimal gland. Dacryocystitis is inflammation of the lacrimal duct or sac. Canaliculitis is inflammation of the canaliculi.

Pathophysiology

Periorbital cellulitis

Periorbital cellulitis can occur by several mechanisms.

• Infection as a result of local trauma including insect bites
• Infection as a result of spread from contiguous structures such as in conjunctivitis, hordeolum, lacrimal system infections, and impetigo
• Infections secondary to hematogenous spread during bacteremia due to nasopharyngeal pathogens
• Infections secondary to sinusitis causing venous and lymphatic congestion

Blepharitis

• Anterior blepharitis is usually caused by bacteria that colonize the base of the eyelashes. If the pilosebaceous glands of Zeiss and Moll become infected an abscess will occur. This abscess is known as a hordeolum or stye. Cell-mediated immunologic mechanisms have been implicated in the development of chronic blepharitis.
• Posterior blepharitis is caused by Meibomian gland dysfunction. The Meibomian gland secretes an oily layer of the tear film. If the secretions become inspissated, causing plugging of the gland, a chalazion develops.

Dacryoadenitis

• Caused by local infection of the lacrimal gland by bacteria or viruses
• Dacryoadenitis associated with inflammation and swelling of the salivary glands is called Mikulicz syndrome. This terminology does not distinguish etiology.

Dacryocystitis

• Caused by inflammation of the lacrimal sac; this usually occurs in the setting of obstruction of the lacrimal apparatus.
• The obstruction may be congenital, secondary to infection, tumor, or trauma.

Canaliculitis

• Caused by infection of the canaliculi; usually chronic
• May also be iatrogenic after instrumentation or placement of silicone plugs in the treatment of dry eyes

Sex

No gender predominance exists.

Age

Periorbital cellulitis is predominantly a pediatric disease. Most cases occur in children younger than 36 months.

Blepharitis caused by Staphylococcus infection was found to occur at a mean age of 42 years. If caused by seborrhea, the mean age was 50 years.

Obstructed lacrimal ducts causing dacryocystitis are common in infants and usually resolve by age 9-12 months.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Periorbital cellulitis
• • An antecedent history of insect bite, trauma to the periorbital skin, infection of adjacent structures, upper respiratory infection, or sinusitis may be present.
  • A sudden increase in temperature and rapid swelling of tissue may occur.
  • A history of underlying illness (eg, HIV acute lymphoblastic leukemia), which would increase the patient's risk of infection, may be present.
• Anterior blepharitis
• • Erythema, pruritus, and crusting of lid margins
  • Typically without discharge
• Posterior blepharitis
• • Epiphora
  • Foreign body or burning sensation
  • Blurred vision, photophobia
• Dacryoadenitis
• • Swelling of upper lateral eyelid
  • Scleral injection
  • If caused by a viral infection, the area is modestly tender. Bacterial causes result in more severe tenderness.
• Dacryocystitis
• • A history of chronic conjunctivitis or recent upper respiratory infection may be present.
    • Epiphora
    • Fever
    • Swelling, tenderness, and erythema usually localized of the medial canthal area
    • Purulent discharge
• Canaliculitis
• • Epiphora
  • Irritation or pruritus of medial portion of affected eyelid

Physical

• Periorbital cellulitis
• • Erythema, swelling, and tenderness of the lids without evidence of orbital congestion (proptosis, decreased extraocular movement)
  • Fever
  • Vesicles if associated with herpetic infection
  • Violaceous discoloration of the lid is more commonly associated with H influenzae.
• Anterior blepharitis
• • Crusting at base of lash (known as scurf or collarettes), erythema of lid
  • Usually, no discharge
  • Poliosis, or whitening of the lash, may occur.
  • If associated with ocular rosacea, telangiectatic vessels may be noted on lid margins and cheeks.
• Posterior blepharitis - Decreased Schirmer score
• Dacryoadenitis
  • Soft tissue swelling that is greatest at the lateral portion of the upper lid margin
  • Deforms the upper lid into a characteristic S-shape
  • If caused by a viral infection, the area is modestly tender. Bacterial causes result in more severe tenderness.
  • Decreased Schirmer score
• Dacryocystitis - Pressure on the area overlying the lacrimal sac may cause expression of purulent material from the lacrimal puncta.
• Canaliculitis
• • Edematous, "pouting" punctum
  • Erythema of adjacent conjunctiva
  • Yellowish concretions may be expressed from the punctum. These are sulfur granules produced by Actinomyces israelii.

Causes

• Periorbital cellulitis
• • When associated with trauma: Staphylococcus aureus and Streptococcus pyogenes (group A streptococci) are most common.
  • In the absence of trauma: Streptococcus pneumoniae; H influenzae type b was the predominant cause prior to the advent of the HiB vaccine.
  • Other unusual causes include Neisseria gonorrhoeae; Neisseria meningitidis; vaccinia virus in a laboratory worker has been reported; herpes simplex virus; and Mycobacterium tuberculosis.
• Anterior blepharitis
• • Almost exclusively caused by Staphylococcus
  • Other bacteria include Propionibacterium acnes and Moraxella species.
  • Helicobacter pylori is associated with blepharitis; but, cause and effect has not been established.
  • Viruses - Herpes simplex virus, herpes zoster virus, and human papillomavirus
  • Mites - Demodex folliculorum
  • Lice - Phthirus pubis causing the condition known as phthiriasis palpebrarum
  • Noninfectious entities such as ocular rosacea and seborrheic dermatitis may also cause anterior blepharitis.
• Posterior blepharitis - Meibomian gland dysfunction
• Dacryoadenitis
• • Bacteria - Most often gram-positive cocci, usually Staphylococci. It may also be caused by Streptococcus pneumoniae.
  • Viruses - Prior to increased immunization rates, the mumps virus was most often implicated. Now, the Epstein-Barr virus is most often associated with chronic dacryoadenitis.
• Dacryocystitis
  • Dacryocystitis usually occurs as a result of obstruction of the lacrimal system, which may be congenital, infectious, secondary to tumor growth, inflammatory, or traumatic.
  • Infectious causes include most commonly Staphylococcus aureus and Streptococcus. Gram-negative bacilli accounted for one fourth of isolates in one study with Escherichia coli most frequently.
• Canaliculitis
  • The most common pathogens are Actinomyces israelii and Nocardia (formerly known as Streptothrix) species.
  • Iatrogenic - Instrumentation or plugging

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Chagas disease
Trichomonas
Nephrotic syndrome
Lice (blepharitis)
Mucormycosis
Idiopathic orbital inflammation, also known as orbital pseudotumor

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Periorbital cellulitis
• • Complete blood count (CBC) with differential is not routinely necessary. It may be helpful if bacteremia or sepsis is a concern.
  • Blood cultures if bacteremia or sepsis is a concern.
  • Consider cerebral spinal fluid studies, especially if H influenzae type b is a likely pathogen.
  • Skin culture has a very low yield.
• Dacryoadenitis
• • CBC with differential and blood culture if bacteremia or sepsis is a concern.
  • Serology testing if viral etiology needs to be established.
• No lab studies are indicated for routine use in dacryocystitis, blepharitis, and canaliculitis.

Imaging Studies

• Periorbital cellulitis
• • Computed tomography (CT) of the orbits should be performed to rule out orbital and subperiosteal involvement and cavernous sinus thrombosis. CT also helps to distinguish sinusitis as cause.
  • CT will show lid edema but no proptosis or "streaking" of the orbital fat, which lies posterior to the orbital septum.
  • MRI is study of choice to rule out cavernous sinus thrombosis.
• Canaliculitis: 20-MHz ultrasound can be used to detect sulfur granules within the canaliculi.

Procedures

• With the exception of lumbar puncture, the procedures listed below are generally performed by specialists outside of the ED.
• • Periorbital cellulitis: If infection with H influenzae type b is suspected or if systemic involvement is present, a lumbar puncture is indicated to exclude meningeal infection.
• Blepharitis: Biopsy may be indicated in some cases to rule out malignancy.
• Dacryoadenitis: Lacrimal gland biopsy may be indicated in chronic disease.
• Schirmer test is used to assess tear production. It is nonspecific as to the etiology of dry eyes.
• Jones dye test is used to assess patency of the lacrimal drainage system. In the first part of the test, a drop of fluorescein is placed in the conjunctival cul-de-sac. After 5 minutes, the nose is examined for the presence of dye. If no dye is present, an obstruction is present and the second part of the test is performed. A cannula is placed into the lacrimal sac, which is then washed with saline. If no fluorescein is noted, the dye is obstructed in the upper (canalicular) portion of the system. If dye is present, then the obstruction is in the lower (sac, duct) portion.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

• Periorbital cellulitis
  • In adult patients who are nontoxic and can be assured of appropriate follow-up, treatment can be as an outpatient on oral antibiotics.
  • Most pediatric cases require admission. Intravenous antibiotics should be started. Once clinical improvement is noted, the patient should be switched to oral antibiotics.
• Blepharitis
• • The treatment of blepharitis, regardless of etiology, begins with eyelid hygiene. The patient should be instructed to wash the lids with a nonirritating baby shampoo or a commercially prepared lid scrubbing solution and to use warm compresses for 15 minutes at a time, 3 or 4 times a day.
  • For blepharitis suspected to be infectious in nature, a topical antibiotic, such as bacitracin or erythromycin, should be prescribed. The frequency and duration of treatment should be determined based on the severity of the disease process. Usually, it is applied 2-4 times a day for 2 weeks.
  • Posterior blepharitis may be treated with an oral tetracycline, which decreases lipase production in staphylococci preventing plugging of Meibomian glands.
  • A brief course of topical steroids has been shown to decrease ocular surface inflammation.
• Dacryoadenitis
  • Treatment of acute dacryoadenitis is largely supportive as the disease is usually self-limiting. Use warm compresses and nonsteroidal anti-inflammatory drugs.
  • If the etiology is bacterial, antibiotic treatment with a first-generation cephalosporin should be started.
  • If etiology is EBV, steroids have been shown to improve the clinical course.
  • For chronic dacryoadenitis, treat the underlying condition.
• Dacryocystitis
  • Treatment with oral antibiotics such as amoxicillin-clavulanic acid or dicloxacillin.
  • In pediatric patients, the obstruction usually resolves by age 9-12 months. Many pediatric ophthalmologists will wait until after this age to probe the ducts to free the obstruction.
  • Dacryocystorhinostomy is the surgical procedure of choice. This procedure allows for the bypassing of the lacrimal duct apparatus as long as the canalicular apparatus is intact.
  • Punctal dilation and nasolacrimal irrigation is contraindicated in the acute stage due to the increased risk of periorbital cellulitis.
• Canaliculitis
  • Remove concretions with gentle pressure on medial aspect of eye.
  • Warm compresses
  • Irrigation with penicillin solution to be performed by an ophthalmologist
  • Systemic antibiotics, usually penicillin or amoxicillin for 1-2 weeks
  • Topical antibiotics - Bacitracin or erythromycin

Consultations

• Consider consultation with ophthalmologist for any patient who may have orbital involvement
• Most cases of lacrimal system infections can be managed conservatively. Consultation with ophthalmologist if the condition is not resolved within 24-48 hours.
• For canaliculitis, an ophthalmologist should be consulted for probing of canaliculi and irrigation with penicillin solution.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goals of pharmacotherapy are to eradicate the infection, prevent complications, and reduce morbidity.

Drug Category: Antibiotics, systemic

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Drug Name	Nafcillin (Nallpen, Unipen)
Description	Initial therapy for suspected penicillin G-resistant streptococcal or staphylococcal infections. Use parenteral therapy initially in severe infections. Change to PO therapy as condition warrants. Due to thrombophlebitis, particularly in the elderly, administer parenterally only for short term (1-2 d); change to PO route as clinically indicated.
Adult Dose	500-2000 mg IV q4-6h; switch to PO dosage form as clinical situation warrants 250-500 mg PO q4-6h, up to 1 g q4-6h for severe infections
Pediatric Dose	Nafcillin is not approved for pediatric use. Off-label dosing is as follows: 100 mg/kg/d IV divided q6h Severe infections: May increase to 200 mg/kg/d IV divided q6h; not to exceed 6-12 g/d; switch to PO dosage form as clinical situation warrants 50-100 mg/kg/d PO divided q6h
Contraindications	Documented hypersensitivity
Interactions	Associated with warfarin resistance when administered concurrently; effects may decrease with bacteriostatic action of tetracycline derivatives
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	To optimize therapy, determine causative organisms and susceptibility; decrease dose in hepatic dysfunction

Drug Name	Amoxicillin and clavulanic acid (Augmentin)
Description	Treats bacteria resistant to beta-lactam antibiotics. For children > 3 mo, base dosing protocol on amoxicillin content. Due to different amoxicillin/clavulanic acid ratios in 250 mg tab (250/125) vs 250 mg chewable tab (250/62.5), do not use 250 mg tab until child weighs more than 40 kg.
Adult Dose	500-875 mg PO bid
Pediatric Dose	In neonates and infants < 3 months: 30 mg/kg/d divided PO q12h In infants > 3 months: 45 mg/kg/d PO divided q12h or 40 mg/kg/d divided q8h Children >40 kg: Administer as in adults
Contraindications	Documented hypersensitivity
Interactions	Coadministration with warfarin or heparin, increases risk of bleeding
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Administer for minimum of 10 d to eliminate organism; some formulations of Augmentin contain phenylalanine (do not give to phenylketonurics); caution in breastfeeding mothers

Drug Name	Cefaclor (Ceclor)
Description	Second-generation cephalosporin indicated for infections caused by susceptible gram-positive cocci and gram-negative rods. Determine proper dosage and route based on condition of patient, severity of infection, and susceptibility of causative organism.
Adult Dose	750-1500 mg/d PO divided bid/tid
Pediatric Dose	>1 month: 20-40 mg/kg/d PO divided q8-12h; not to exceed 1 g/d
Contraindications	Documented hypersensitivity
Interactions	Alcoholic beverages consumed <72 h after ingestion may produce disulfiramlike reactions; may increase hypoprothrombinemic effects of anticoagulants; coadministration with potent diuretics and aminoglycosides (eg, loop diuretics) may increase nephrotoxicity
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Risk of toxic reactions may be greater in patients with impaired renal function; Administer half dose if CrCl is 10-30 mL/min and one-quarter dose if <10 mL/min; fungal and microorganism overgrowth may occur with prolonged therapy

Drug Name	Tetracycline (Sumycin)
Description	Treats gram-positive and gram-negative organisms as well as mycoplasmal, chlamydial, and rickettsial infections. Inhibits bacterial protein synthesis by binding with 30S and, possibly, 50S ribosomal subunit(s).
Adult Dose	250 mg PO q6h; alternatively, 500 mg PO q12h
Pediatric Dose	<8 years: Not recommended >8 years: 25-50 mg/kg/d PO divided q6h; not to exceed 3 g/d
Contraindications	Documented hypersensitivity; severe hepatic dysfunction
Interactions	Bioavailability decreases with antacids containing aluminum, calcium, magnesium, iron, or bismuth subsalicylate; can decrease effects of PO contraceptives, causing breakthrough bleeding and increased risk of pregnancy; tetracyclines can increase hypoprothrombinemic effects of anticoagulants
Pregnancy	D - Unsafe in pregnancy
Precautions	Photosensitivity may occur with prolonged exposure to sunlight or tanning equipment; reduce dose in renal impairment; consider drug serum level determinations in prolonged therapy; use during tooth development (last half of pregnancy through age 8 y) can cause permanent tooth discoloration; Fanconilike syndrome may occur with outdated tetracyclines

Drug Name	Bacitracin (AK-Tracin)
Description	Prevents transfer of mucopeptides into growing cell wall, inhibiting bacterial growth.
Adult Dose	Apply 0.25- to 0.5-inch ribbon q3-4h for 7-10 d into conjunctival sac(s)
Pediatric Dose	Administer as in adults
Contraindications	Documented hypersensitivity; vaccinia, varicella, epithelial herpes simplex keratitis, mycobacterial infections, fungal diseases of the eye; patients using steroid combinations after uncomplicated removal of a corneal foreign body
Interactions	None reported
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Ophthalmic ointments may delay healing of corneal epithelia; in deep-seated infections of the eye, supplement with systemic medications; prolonged use may result in overgrowth of nonsusceptible organisms

Drug Name	Erythromycin (E-Mycin)
Description	Macrolide antibiotic that binds to 50S ribosomal subunit blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Does not affect nucleic acid synthesis. Indicated for infections caused by susceptible strains of microorganisms and for prevention of corneal and conjunctival infections.
Adult Dose	Apply 0.5-inch (1.25 cm) ribbon 2-8 times/d depending on severity of infection
Pediatric Dose	Apply as in adults
Contraindications	Documented hypersensitivity; hepatic impairment
Interactions	Coadministration may increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; coadministration with lovastatin and simvastatin, increases risk of rhabdomyolysis; decreases metabolism of repaglinide, thus increasing serum levels and effects
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Caution in liver disease; estolate formulation may cause cholestatic jaundice; GI side effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Indicated for the treatment of periorbital cellulitis in the pediatric population for the administration of intravenous antibiotics
• Indicated in any patient who is septic or has orbital involvement
• Hospital admission for intravenous antibiotics may be required for patients younger than 3 months who have dacryocystitis.

Complications

• Periorbital cellulitis
• • CNS infections - Meningitis, epidural abscess, subdural empyemas, brain abscess
  • Orbital involvement - Cellulitis, abscess
  • Cavernous sinus thrombosis
  • Toxic shock syndrome
  • Eschar formation leading to scarring
• Blepharitis
  • Hordeolum
  • Chalazion
  • Scarring
  • Trichiasis (misdirection of eyelashes)
  • Corneal infection
• Dacryocystitis - Complications may occur during a dacryocystorhinostomy, including hemorrhage, infection, and CSF leakage.

Prognosis

• Periorbital cellulitis - With appropriate antibiotics, the prognosis is good.
• Blepharitis - Typically, this is a chronic disease with waxing and waning of symptoms.
• Dacryoadenitis
• • Prognosis of the acute form is excellent as it is a self-limiting process.
  • Prognosis of the chronic form depends on the underlying disease process.
• Dacryocystitis - Success rates for dacryocystorhinostomy are good. External procedures fare better due to the ability to create a larger ostium.

Patient Education

• Periorbital cellulitis - For excellent patient education resources see eMedicine's patient education article, Cellulitis.
• Blepharitis - Blepharitis Fact Sheet is available for purchase from the American Academy of Ophthalmology.
• The use of eye makeup, especially eyeliner, can cause acute exacerbations by plugging the glands.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to recognize orbital involvement.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Aburn NS, Sullivan TJ. Infectious mononucleosis presenting with dacryoadenitis. Ophthalmology. May 1996;103(5):776-8. [Medline].
• American Academy of Ophthalmology. Preferred Practice Patterns: Blepharitis. Accessed May 14, 2006. [Full Text].
• Boruchoff SA, Boruchoff SE. Infections of the lacrimal system. Infect Dis Clin North Am. Dec 1992;6(4):925-32. [Medline].
• Carter SR. Eyelid disorders: diagnosis and management. Am Fam Physician. Jun 1998;57(11):2695-702. [Medline].
• Chand DV, Hoyen CK, Leonard EG. First reported case of Neisseria meningitidis periorbital cellulitis associated with meningitis. Pediatrics. Dec 2005;116(6):e874-5. [Medline].
• Charles NC, Lisman RD, Mittal KR. Carcinoma of the lacrimal canaliculus masquerading as canaliculitis. Arch Ophthalmol. Mar 2006;124(3):414-6. [Medline].
• Cummings C, Haughey B, Thomas R, et al. Cummings Otolaryngology: Head and Neck Surgery. 4th ed. 2005:771.
• Gershon:. Krugman's Infectious Diseases of Children. 11th ed. 2004:163.
• Givner LB, Mason EO, Barson WJ. Pneumococcal facial cellulitis in children. Pediatrics. Nov 2000;106(5):E61. [Medline].
• Green JA, Lim J, Barkham T. Neisseria gonorrhoeae: a rare cause of preseptal cellulitis?. Int J STD AIDS. Feb 2006;17(2):137-8. [Medline].
• Greenberg MF, Pollard ZF. The red eye in childhood. Pediatr Clin North Am. Feb 2003;50(1):105-24. [Medline].
• Lee J, Flanagan JC. Complications associated with silicone intracanalicular plugs. Ophthal Plast Reconstr Surg. Nov 2001;17(6):465-9. [Medline].
• Lewis FM, Chernak E, Goldman E. Ocular vaccinia infection in laboratory worker, Philadelphia, 2004. Emerg Infect Dis. Jan 2006;12(1):134-7. [Medline].
• Noble. Textbook of Primary Care Medicine. 3rd ed. 2001:1693.
• Raina UK, Jain S, Monga S. Tubercular preseptal cellulitis in children: a presenting feature of underlying systemic tuberculosis. Ophthalmology. Feb 2004;111(2):291-6. [Medline].
• Rhem MN, Wilhelmus KR, Jones DB. Epstein-Barr virus dacryoadenitis. Am J Ophthalmol. Mar 2000;129(3):372-5. [Medline].
• Sacca SC, Pascotto A, Venturino GM. Prevalence and treatment of Helicobacter pylori in patients with blepharitis. Invest Ophthalmol Vis Sci. Feb 2006;47(2):501-8. [Medline].
• Schwartz GR, Wright SW. Changing bacteriology of periorbital cellulitis. Ann Emerg Med. Dec 1996;28(6):617-20. [Medline].
• Thappa DM, Karthikeyan K, Jeevankumar B. Phthiriasis palpebrarum. Postgrad Med J. Feb 2003;79(928):102. [Medline].
• Tost F, Bruder R, Clemens S. Clinical diagnosis of chronic canaliculitis by 20-MHz ultrasound. Ophthalmologica. 2000;214(6):433-6. [Medline].
• Wald ER. Periorbital and orbital infections. Pediatr Rev. Sep 2004;25(9):312-20. [Medline].
• Yanoff. Ophthalmology. 2nd ed. 2004:761.

Article Last Updated: Sep 5, 2006