What are the differential diagnoses for a stye?

Differential Diagnoses for a Stye (Hordeolum)

The primary differential diagnoses for a stye include chalazion, blepharitis, sebaceous carcinoma, preseptal cellulitis, and other eyelid inflammatory conditions that can mimic acute eyelid inflammation. 1, 2, 3

Key Differentiating Features

Chalazion vs. Hordeolum (Stye)

• Chalazion presents as a painless, firm nodule within the tarsal plate with gradual onset, often associated with meibomian gland obstruction visible on eyelid eversion, whereas a hordeolum is acutely painful with rapid onset and erythema at the eyelid margin 3, 4
• Chalazia develop from chronic lipogranulomatous inflammation due to retained sebaceous secretions, while hordeola represent acute purulent infections often involving eyelash follicles or glands 4
• The clinical course differs significantly: chalazia persist for months and rarely resolve spontaneously, while hordeola typically resolve within 5-14 days with conservative management 3, 4

Blepharitis

• Chronic blepharitis presents with bilateral eyelid margin inflammation, crusting at lash bases, loss or misdirection of eyelashes, and recurrent hordeola rather than a single acute lesion 1, 2
• Morning symptoms with eyelid sticking, burning, and irritation suggest underlying blepharitis as a predisposing condition rather than an isolated hordeolum 2
• Look for abnormal deposits at the base of eyelashes, vascularization of eyelid margins, and meibomian gland dysfunction on slit-lamp examination 1

Sebaceous Carcinoma (Critical Red Flag)

• Unilateral chronic "blepharitis" or recurrent chalazia in the same location that are unresponsive to therapy should raise immediate suspicion for sebaceous carcinoma, particularly in elderly patients 1, 2, 3
• Warning signs include marked asymmetry, focal lash loss (ciliary madarosis), loss of normal eyelid margin anatomy, and unifocal recurrent lesions 1, 2, 3
• Biopsy is indicated when lesions show resistance to therapy, especially with conjunctival cicatricial changes in the affected eye 1, 2

Preseptal Cellulitis

• Severe viral conjunctivitis with marked eyelid swelling and erythema can mimic orbital or preseptal cellulitis 5
• Differentiate by presence of purulent discharge, fever, and systemic signs in cellulitis versus watery discharge and follicular conjunctival reaction in viral conjunctivitis 5

Other Inflammatory Conditions

• Giant papillary conjunctivitis presents with chronic papillary reaction of superior tarsal conjunctiva, often associated with contact lens wear, rather than localized eyelid margin inflammation 1
• Floppy eyelid syndrome shows upper eyelid edema with easily everted lids and diffuse papillary reaction, typically bilateral and associated with obesity 1
• Conjunctival chalasis presents with redundant conjunctiva and eyelid margin overhang, causing chronic irritation rather than acute inflammation 1

Clinical Approach to Differentiation

History Elements

• Onset timing: abrupt onset with rapid progression suggests hordeolum; gradual onset suggests chalazion 3
• Pain severity: moderate to severe pain indicates hordeolum; minimal or no pain suggests chalazion 3
• Recurrence pattern: multiple episodes or same-location recurrence raises concern for underlying conditions or malignancy 2, 3
• Associated symptoms: concurrent upper respiratory infection suggests viral conjunctivitis; systemic rosacea or seborrheic dermatitis suggests predisposition to meibomian gland dysfunction 1, 2

Physical Examination Findings

• Location: eyelid margin involvement with purulent discharge indicates hordeolum; deeper tarsal plate nodule suggests chalazion 3
• Eyelid eversion: visible meibomian gland obstruction confirms chalazion; acute inflammation at gland orifice suggests hordeolum 1, 3
• Conjunctival examination: follicular reaction suggests viral etiology; papillary reaction suggests bacterial or allergic causes 5
• Preauricular lymphadenopathy: presence suggests viral conjunctivitis or hypervirulent bacterial infection 5

When to Pursue Further Evaluation

• Obtain eyelid biopsy for unilateral chronic lesions unresponsive to standard therapy, recurrent chalazia at the same site, or any lesion with focal lash loss 1, 2, 3
• Consider microbiologic cultures for recurrent hordeola with severe inflammation or failure to respond to initial therapy 1, 2
• Evaluate for Demodex infestation with microscopic examination of epilated eyelashes if persistent blepharitis with lash collarettes is present 1, 2
• Assess for underlying systemic conditions including rosacea, atopic dermatitis, seborrheic dermatitis, or medication effects (isotretinoin, dupilumab) in recurrent cases 1, 2

Common Diagnostic Pitfalls

• Failing to recognize sebaceous carcinoma masquerading as chronic blepharitis or recurrent chalazion, particularly with unilateral presentation 1, 2, 3
• Missing underlying chronic blepharokeratoconjunctivitis in pediatric patients with recurrent chalazia, which can lead to amblyopia if untreated 2
• Overlooking medication-induced blepharitis from isotretinoin or dupilumab in patients with new-onset or worsening eyelid inflammation 2
• Assuming all eyelid swelling is infectious when severe viral conjunctivitis can mimic preseptal cellulitis 5