**2. Eyelid infections**

Infections of the eyelid include external and internal hordeolum [1]. The first one is abscess localized in the anterior lamella of the eyelid (orbicularis), whereas the internal is located in the posterior lamella (tarsus). Pain and swelling, redness, local tenderness and warmth of the eyelid characterize both. The swelling is well localized. When it is more diffuse, secondary preseptal cellulitis exists.

Preseptal cellulitis is diffuse swelling of one of the eyelids or both [2]. It includes the triad of tenderness (dolor), redness (color) and warmth (calor). The usual cause is eyelid abrasion by trauma. Preseptal cellulitis is distinguished from the more severe orbital cellulitis by the absence of proptosis, limitation of ocular movements and involvement of the optic disc (swelling) because the infection is confined anteriorly by the orbital septum.

Primary herpes simplex infection is characterized by small vesicle on the eyelid that may be accompanied by conjunctival hyperemia [3]. Necrotizing fasciitis is a rapidly progressive infection of the subcutaneous soft tissues that spreads through the fascia and may involve the eyelid and the orbit [4]. The first sign is skin erythema that spreads quickly and changes its color to purple. Later, the skin and subcutaneous tissues may separate from the deep tissues. The patient becomes toxic and suffers of severe local pain. It may be idiopathic or appear after trivial trauma or surgery. The most common causative agents are A streptococci, clostridium (with gas gangrene) and polymicrobial. Since the disease is fatal, early detection and treatment are essential.

Blepharitis is an bilateral inflammation of the eyelid margins that may be caused by infective agents (**Figure 1**) [5]. Seborrheic blepharitis causes scales over the eyelids and may accompany seborrhea. Staphylococcal blepharitis is clinically characterized by collarettes around the eyelash bases that move along the hair shaft as it grows. It is caused by staphylococcal species. Demodex blepharitis is characterized by sleeves along the base of the lash shaft and is caused by *Demodex folliculorum*. The eyelid margins may be erythematous. Patients may complain for ocular irritation, burning sensation, dryness or bouts of dryness and tearing. They may complain of stickiness or ocular tiredness/tense. Blepharitis may be accompanied by conjunc‐ tivitis (i.e. blepharoconjunctivitis) and in this case the eyelid margins show identical signs to blepharitis but the conjunctiva is also inflamed.

Phthiriasis palpebrarum is an infestation of the eyelid margins caused by *Phthirus pubis* [6]. Eggs and adults are found near the base of the eyelashes. Patients may complain from irritation. They are usually from nursery homes and the disease is sexually transmitted.

**Figure 1.** Blepharitis. Note the scales at the base of the eyelashes.

Identifying and treating ocular infections can be challenging. Ocular infections may share identical clinical result and be caused by different etiologic agents. The infection is usually named according to the ocular structures involved with the suffix "itis" meaning infectious or

Infections of the eyelid include external and internal hordeolum [1]. The first one is abscess localized in the anterior lamella of the eyelid (orbicularis), whereas the internal is located in the posterior lamella (tarsus). Pain and swelling, redness, local tenderness and warmth of the eyelid characterize both. The swelling is well localized. When it is more diffuse, secondary

Preseptal cellulitis is diffuse swelling of one of the eyelids or both [2]. It includes the triad of tenderness (dolor), redness (color) and warmth (calor). The usual cause is eyelid abrasion by trauma. Preseptal cellulitis is distinguished from the more severe orbital cellulitis by the absence of proptosis, limitation of ocular movements and involvement of the optic disc

Primary herpes simplex infection is characterized by small vesicle on the eyelid that may be accompanied by conjunctival hyperemia [3]. Necrotizing fasciitis is a rapidly progressive infection of the subcutaneous soft tissues that spreads through the fascia and may involve the eyelid and the orbit [4]. The first sign is skin erythema that spreads quickly and changes its color to purple. Later, the skin and subcutaneous tissues may separate from the deep tissues. The patient becomes toxic and suffers of severe local pain. It may be idiopathic or appear after trivial trauma or surgery. The most common causative agents are A streptococci, clostridium (with gas gangrene) and polymicrobial. Since the disease is fatal, early detection and treatment

Blepharitis is an bilateral inflammation of the eyelid margins that may be caused by infective agents (**Figure 1**) [5]. Seborrheic blepharitis causes scales over the eyelids and may accompany seborrhea. Staphylococcal blepharitis is clinically characterized by collarettes around the eyelash bases that move along the hair shaft as it grows. It is caused by staphylococcal species. Demodex blepharitis is characterized by sleeves along the base of the lash shaft and is caused by *Demodex folliculorum*. The eyelid margins may be erythematous. Patients may complain for ocular irritation, burning sensation, dryness or bouts of dryness and tearing. They may complain of stickiness or ocular tiredness/tense. Blepharitis may be accompanied by conjunc‐ tivitis (i.e. blepharoconjunctivitis) and in this case the eyelid margins show identical signs to

Phthiriasis palpebrarum is an infestation of the eyelid margins caused by *Phthirus pubis* [6]. Eggs and adults are found near the base of the eyelashes. Patients may complain from irritation.

They are usually from nursery homes and the disease is sexually transmitted.

(swelling) because the infection is confined anteriorly by the orbital septum.

noninfectious inflammation.

4 Advances in Common Eye Infections

**2. Eyelid infections**

preseptal cellulitis exists.

are essential.

blepharitis but the conjunctiva is also inflamed.

Treatment for localized infection such as hordeolum include warm dry compresses 3–4 times a day for 10 min each and antibiotic ointment until complete resolution is achieved or drainage, if possible. Preseptal cellulitis is treated by antibiotics such as amoxicillin trihydrate 875 mg with clavulanic acid 125 mg (Augmentin®) bid or ceftazidime 1 g/day PO or IV for a week.

Blepharitis can be prevented by eyelid hygiene. Blepharitis is treated by warm dry compresses followed by massage with tetracycline ointment for staphylococcal and seborrhea forms and fusidic acid (Fucithalmic®) for demodex. Topical azithromycin 1% is also very effective. In refractory cases, systemic antibiotics from the tetracycline family such as doxycycline 100 mg 1qd, tetracycline 250 mg qid or azithromycin 200 mg/day PO is added. Terpinen‐4‐ol, the main component of the essential oil of *Melaleuca alternifolia* (tea tree oil) has been demonstrated for Demodex. Blepharoconjunctivitis is treated similarly with an additional mild topical cortico‐ steroid (such as fluorometholone (FML®) 0/1% qid or loteprednol (Lotemax®) 0.5% qid) for limited period or tear substitutes. Phthiriasis palpebrarum is treated by manual removal of all the mites and ova and treatment of the pubis with yellow mercuric oxide 1%. Necrotizing fasciitis is treated under hospitalization usually in intensive care unit. Treatment includes intravenous penicillin V 500 mg bid or intramuscular benzathine penicillin G 1.2 million units qid, aminoglycoside (e,g., gentamicin 1‐1.5mg/kg/day IV tid) and clindamycin 600 mg IV tid in combination with surgical debridement and hyperbaric oxygen. patients that are allergic to penicillin receive either vancomycin 1 g bid and aztreonam 1 g tid with clindamycin instead of penicillin.
