Eyelid Swelling

Anatomy

Zeis gland = sebaceous gland of eyelash (external)
Moll gland = apocrine gland of external eyelid
Meibomian gland = sebaceous gland of internal eyelid

Pathology

Infxn of Meibomian = internal hordeolum (internal stye)
Infxn of Zeis or Moll = external hordeolum (external stye)
Blocked Meibomian that is not infected (no pain, no erythema) = Chalazion

Internal hordeolums can resolve into chalazions.
Blepharitis can cause meibomian gland to stop up, leading to chalazions.

Appearance

Hordeolums and Chalazions look like distinct lumps.
Blepharitis look like red swollen sore margins of eyelids, bilateral.
Periorbital (preseptal) cellulitis look like whole eye area is swollen, but no proptosis.
Orbital (postseptal) cellulitis look like whole area swollen with proptosis.

Treatment

Int and ext hordeolum same tx – warm compress + topical abx (erythro, bacitracin). Inc/drain if doesnt work.
Chalazion tx – incision/drain, or inject triamcinolone.
Periorbital cellulitis tx – PO Abx i.e. Cephalexin.
Orbital cellulitis tx – IV Abx i.e. Unasyn or Vancomycin (if suspect MRSA), then PO Augmentin.