AKT · Ophthalmology/Orbit & infection

Preseptal (periorbital) cellulitis

Infection ANTERIOR to the orbital septum (eyelid soft tissue)

Overview

Infection of the eyelid and periocular soft tissue ANTERIOR to the orbital septum, without orbital involvement. Presents with a red, swollen, tender lid but — crucially — NORMAL eye movements, NO proptosis and NORMAL vision/colour. Treated with oral antibiotics; the essential skill is distinguishing it from sight- and life-threatening orbital cellulitis.

Recognise

Unilateral red, swollen, warm, tender eyelid, often following local infection (stye, insect bite, sinusitis, trauma)
NORMAL eye movements, NO proptosis, NO pain on eye movement, NORMAL visual acuity and colour vision, NO RAPD
Systemically usually well; commoner in children

Red flags

ANY of: proptosis, painful/restricted eye movements, reduced acuity/colour vision, RAPD, marked systemic illness → ORBITAL cellulitis — admit for IV antibiotics + CT
Rapid progression or not settling on oral antibiotics → reassess as orbital

Differentials & how to tell them apart

Orbital (post-septal) cellulitisproptosis, painful/restricted eye movements, reduced vision/colour, RAPD, systemically unwell — an emergency

Allergic lid oedemaitchy, bilateral, not hot/tender, no fever

Dacryocystitislocalised tender swelling at the medial canthus

Insect bite/contact dermatitisitch, no systemic upset

Investigations

Clinical. The key is examining eye movements, vision, colour and pupils (all normal in preseptal). CT orbits/sinuses if orbital cellulitis cannot be excluded.

Management

Oral co-amoxiclav + safety-net; admit if any orbital signs

1Seek specialist advice and prescribe oral co-amoxiclav (clarithromycin + metronidazole if penicillin-allergic). Safety-net and review within 24–48 h.Gate: Examine eye movements, acuity, colour vision and pupils EVERY time — any proptosis, painful/restricted movement, reduced vision/colour or RAPD means ORBITAL cellulitis → admit for IV antibiotics and CT, not oral treatment
2Not improving or any orbital feature → admit, IV antibiotics, urgent CT orbits/sinuses and ENT/ophthalmology input.

Oral co-amoxiclav — first-line (covers eye/nose-region organisms)

Clarithromycin (+ metronidazole) if penicillin-allergic — per NICE cellulitis near the eyes/nose

Key points

Preseptal = lid only: movements, vision, colour and pupils are NORMAL. The whole skill is screening for the orbital signs that turn it into an emergency.

Monitor & prognosis

Review at 24–48 h; low threshold to escalate.

Good with oral antibiotics if truly preseptal.

Source: NICE CKS Cellulitis – acute; CREST