MICROBIAL DISEASES OF THE EYES AND SKIN Flashcards by M.A.Lance Evangelista

The Etiological agents that may affect the eyes will
vary depending on the ______ of tissue
affected

area and type

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Disease spread may be divided into:

➔ Eyelids and tissue surrounding the eyes
➔ Conjunctiva
➔ Cornea
➔ Intraocular area

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BLEPHARITIS
● Etiological agent are

Demodex folliculorum (a mite)

Followed by bacterial infection Staphylococcus aureus
or Staphylococcus epidermidis

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Diagnosis : Due to an allergic reaction to the mite
which resides in the eyelash or the eyebrow

BLEPHARITIS

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Abscesses
may form in and around the follicles, destroying the
follicles, with the loss of lashes and the formation of
ulcers.

BLEPHARITIS

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BLEPHARITIS
Treatment:

Glucocorticoid
Doxycycline or Minocycline
Azithromycin

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Glucocorticoid-______

for the allergic reaction

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There may be a history of itching and scaling
of the lid since early childhood. The patient
describes an incessant urge to pull on the
lashes in an attempt to remove the scales

BLEPHARITIS

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HORDEOLUM AND CHALAZION
● Etiological agents are generally

Staphylococcus
aureus, but may also be caused by Pseudomonas
aeruginosa and Proteus spp.

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Diagnosis: Obstruction of the orifice of a gland
(_____,_____,____) seems to be the primary
pathological event in the formation of hordeolum (______)

HORDEOLUM AND CHALAZION

Meibomian, Zeis, or Moll

Stye

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A red nodule that is quite painful develops and is
surmounted with a yellowish top as the lesion matures.

HORDEOLUM AND CHALAZION

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HORDEOLUM AND CHALAZION
The histopathology is typical of

acute suppurative
inflammation

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(untreated stye) evolved from
hordeolum that do not drain spontaneously or
are not incised.

Chalazion

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HORDEOLUM AND CHALAZION

There is usually persistent chronic
inflammation, and ______ may
occur as sebaceous secretions are impounded.

granuloma formation

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HORDEOLUM AND CHALAZION
Treatment:

Erythromycin
Cefalexin
Doxycycline

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Treatment

for susceptible strains and for
prevention of corneal and conjunctival
infections

Erythromycin:

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may be added if there recurrent
lesions or significant meibomitis

Doxycycline:

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PERIORBITAL CELLULITIS
● Etiological agent are

Staphylococcus aureus (most
common), S. pneumoniae, H. influenzae

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PERIORBITAL CELLULITIS
Also known as

periseptal cellulitis

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PERIORBITAL CELLULITIS
Diagnosis: Characterized by

acute eyelid erythema
and edema

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PERIORBITAL CELLULITIS
Treatment

Clindamycin as empirical therapy
Doxycycline, cotrimoxazole

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ACUTE DACROCYSTITIS
● Etiological agent are

Staphylococcus aureus,
Staphylococcus epidermidis and Streptococcus
Pneumoniae

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Diagnosis:
➔ This is an infection of the lacrimal sac,
almost always secondary to obstruction of the
lacrimal duct.

ACUTE DACROCYSTITIS

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Occurs when both the upper and lower ends of
the drainage system become partially or totally
obstructed. The major symptom is pain in the
tear sac area. There are also erythema,
edema, a purulent discharge and epiphora

ACUTE DACROCYSTITIS

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ACUTE DACROCYSTITIS Treatment

➔ Coamoxiclav, Sultamicillin (sulbactam + ampicillin) , Levofloxacin (fluoroquinolone) ➔ Tobramycin ophthalmic ➔ Tobramycin plus dexamethasone ophthalmic (too much inflammation)

are immunosuppressants which suppresses the immune action like inflammation, redness and swelling.

Glucocorticoids

CHRONIC DACROCYSITITIS ● Etiological agents are

Streptococcus pneumoniae, Haemophilus influenzae, Candida albicans ,Aspergillus sp., Actinomyces sp.

is usually caused by a single site of partial or complete obstruction within the lacrimal sac or within the nasolacrimal duct. The infection is usually the result, and not the cause, of obstruction

CHRONIC DACROCYSITITIS

CHRONIC DACROCYSITITIS Obstruction may be due to:

➔ Trauma ➔ Tumors ➔ Foreign bodies ➔ Delayed canalization in neonates ➔ Closure of canal in postmenopausal women

(Sore eyes)

PINK EYE CONJUNCTIVITIS

PINK EYE CONJUNCTIVITIS (Sore eyes) ● Etiological agent are

Haemophilus aegypticus and/or Moraxella lacunata

Diagnosis: The only symptoms are conjunctivitis, either chronic or acute, and severe inflammation of the cornea. Diagnosis is via isolation of the organism ( Gam-negative slender rod).

PINK EYE CONJUNCTIVITIS (Sore eyes)

PINK EYE CONJUNCTIVITIS (Sore eyes) Treatment

➔Topical sulfacetamide, erythromycin, ciprofloxacin or ofloxacin. ➔ NEW agent: besifloxacin: Opthalmic suspension

Ocular Lymphogranuloma Venereum ● Etiological agent:

Chlamydia trachomatis

Diagnosis: ➔ This is a chlamydial disease transmitted to the fetus during passage down the birth canal (vertical transmission)

Ocular Lymphogranuloma Venereum

Inflammation begins about five days after birth and never results in follicle formation (thus, it differs from trachoma and inclusion conjunctivitis).

Ocular Lymphogranuloma Venereum

Corneal scars, conjunctival scars, and micropannus formation occur.

Ocular Lymphogranuloma Venereum

It is rarely a cause of blindness.

Ocular Lymphogranuloma Venereum

Ocular Lymphogranuloma Venereum Treatment

Azithromycin, Erythromycin, Doxycycline (DOC) but caution in children

Trachoma ● Caused by

Chlamydia trachomatis

This disease is limited to man, infecting only epithelial cells of the eye and possibly the nasopharynx; no systemic involvement has been described. It is found worldwide, and is the greatest single cause of blindness.

Trachoma

Scarring of the conjunctiva may cause the eyelids to turn inward so that the lashes scratch the cornea

Trachoma

Pink, smooth, thin and transparent. Over the whole area of the tarsal conjunctiva, there are large deeplying blood vessels that run vertically

Normal Tarsal Conjunctiva

Presence of five or more follicles in the upper tarsal conjunctiva ➔ Follicles are round swellings that are paler than the surrounding conjunctiva, appearing white, grey or yellow ➔ 0.5 mm in diameter

(TF)Trachomatous Inammation- follicular

Pronounced inflammatory thickening of the tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels in ➔ The tarsal conjunctiva appears red, rough and thickened, with numerous follicles which may be covered by the thickened conjunctiva

(TI)Trachomatous Inammation-Intense

● Scars are visible as white lines or sheets in the tarsal conjunctiva. They are glistening and fibrous in appearance.

Trachomatous scarring (TS)

_____especially diffuse fibrosis, may obscure the tarsal blood vessels

Scarring,

● At least one eyelash rubs on the eyeball ● Evidence of recent removal of inturned eyelash

Trachomatous Trichiasis (TT)

The pupil margin is blurred viewed through the opacity. Such corneal opacities cause significant visual impairment ( less than 6/18 or 0.3 vision) and visual acuity should also be measured

corneal opacity

Trachoma Treatment

● DOC for trachoma: Azithromycin ● Alternative: 1% tetracycline ointment

VIRAL CONJUNCTIVITIS ● Etiological agents are

-Adenovirus types 3,7 and 8, -Human Herpesvirus 1 (Herpes simplex 1 virus) , -Human Herpesvirus 2 (Herpes simplex 2 virus), -Varicella-Zoster virus and -Cytomegalovirus

Diagnosis: Bilateral conjunctivitis which is usually self limited. No constitutional symptoms are present

VIRAL CONJUNCTIVITIS

VIRAL CONJUNCTIVITIS Treatment:

➔ Artificial tears ➔ Azalastine ophthalmic Ketotifen

Relatively selective H1 receptor antagonist that inhibits the release of mast cell

Ketotifen

caused by a virus, like the common cold. This type of pink eye is very contagious, but usually will clear up on its own within several days without medical treatment .

Viral conjunctivitis

Caused by eye irritants such as pollen, dust and animal dander among susceptible individuals. Allergic conjunctivitis may be seasonal (pollen) or flare up year-round (dust; pet dander)

Allergic Conjunctivitis -

caused by bacteria, this type of conjunctivitis can cause serious damage to the eye it left untreated

Bacterial conjunctivitis

VIRAL CONJUNCTIVITIS ● Etiological agents are

Candida albicans, Sporothrix schenkii, Allescheria sp., Aspergillus sp., Mucor sp

Diagnosis: An uncommon disease which can be acute or chronic. Often secondary to fungal infections of other parts of the body. Often aggravated by glucosteroids and initiated after antibiotic therapy. Diagnosed by isolation of the etiological agent

VIRAL CONJUNCTIVITIS

VIRAL CONJUNCTIVITIS Treatment

➔ Natamycin: Initial drug for fusarium disease ➔ Amphotericin B: First agent of choice for corneal infections due to yeast such as candida ➔ Azoles: For Fusarium, Aspergillus, Curvilaria and Candida ➔ Flucytosine: Active against Candida and Cryptococcus ➔ Voriconazole: DOC for aspergillus, Fusarium Blastomyces, Coccidiodes, Curvularia and other fungal infection - azole that inhibits the conversion of lanosterol to ergosterol

PARASITIC CONJUNCTIVITIS:

Onchocerciasis African eye worm

River blindness

(Onchocerca vulvulus)

Onchocerciasis: transmitted by

simulium blackflies

Second leading cause of blindness in the world

Onchocerciasis

Onchocerciasis Treatment

Ivermectin Moxidectin Doxycycline

a macrolytic lactone for 12 yrs and older, does not kill adult O. vulvulus

Moxidectin

may be used to eliminate the endosybiotic bacteria Woblachia; this disrupts production of microfilariae by the adult female worm

Doxycycline

African eye worm

LOA LOA

LOA LOA Transmitted by

Chrysops deer fly

LOA LOA ● Treatment:

Diethylcarbamazine Albendazole

Serves as inhibitor of arachidonic acid metabolism in microfilaria Available only through CDC

Diethylcarbamazine

For treatment of symptomatic loiasis with parasitemia of 8000 microfilariae/mL

Albendazole

OPHTHALMIA NEONATORUM ● Etiological agent is

Neisseria gonorrhoeae

Diagnosis: The disease is contracted from a mother with gonorrhea as the fetus passes down the birth canal. Infection does not occur in utero. At one time about 10% of all cases of blindness in the United States was due to this disease.

OPHTHALMIA NEONATORUM

OPHTHALMIA NEONATORUM major clinical sign

Corneal inflammation

OPHTHALMIA NEONATORUM Treatment

➔ Erythromycin oral or ointment ★ Systemic treatment is necessary ➔ Silver nitrate drops ( rarely used now) ★ May be used to prevent disease

Inflammation of the cornea

BACTERIA KERATITIS

➔ Rapid progression ➔ Corneal destruction may occur in 24-48 hours (blindness)

BACTERIA KERATITIS

BACTERIA KERATITIS Features:

Corneal ulceration, stromal abscess formation, surrounding corneal edema and anterior segment inflammation

BACTERIA KERATITIS Etiological agents:

Streptococcus, Pseudomonas, Enterobacteriaceae ( Klebsiella, Enterobacter, Serratia and Proteus), Staphylococcus

BACTERIA KERATITIS Treatment

➔ Tobramycin (14 mg/mL) ★ 1 drop every hour, alternating with fortified cefazolin or vancomycin. ➔ Fourth-Generation Fluoroquinolones ★ Moxifloxacin and Gatifloxacin : Penetrates better than Gati ➔ New Fluoroquinolone : Besifloxacin ★ Approved in 2009 for bacterial conjunctivitis.

_____ species is the most common isolate in fungal keratitis world wide, followed by _____ and _____

Aspergillus Fusarium penicillium

● More common in men than in women ● May be acquired through unhygienic contact lens use ● This may extend from the cornea to the sclera and intraocular structures

FUNGAL KERATITIS

FUNGAL KERATITIS May cause

scleritis, endopthlamitis, panopthalmitis

Very difficult to treat and may result to visual loss and loss of eye

FUNGAL KERATITIS

FUNGAL KERATITIS Treatment

Ampothericin B Natamycin

Common causes of Anterior uveitis

➔ Mumps virus, Human Herpesvirus 3 (Varicella-Zoster virus), Rubella virus, Rubeola virus, Human Herpesvirus 1 (Herpes simplex 1 virus)

Common causes of Posterior uveitis:

➔ Toxoplasma gondii (25% of all cases) Toxocara sp., Cryptococcus neoformans, Histoplasma capsulatum, Mycobacterium tuberculosis, Cytomegalovirus, Herpessimplex 1 virus, Human immunodeficiency virus

MICROBIAL DISEASES OF THE EYES AND SKIN Flashcards

(88 cards)