Itchy or Irritating Eyes or Eyelids
This is a nuisance symptom which patients present with directly, or via their optician. It can be very difficult to ascertain whether the problem is arising from the eyelid or the eye itself. Often, the symptoms affect both and the causes overlap – which is why they’re considered together here.
Differential diagnosis
Common Diagnoses
- Allergic Conjunctivitis (Usually Hay Fever)
- Infective Conjunctivitis
- Dry Eyes
- Blepharitis
- Blocked Tear Duct
Occasional Diagnoses
- Ectropion
- Entropion
- Eczema of the Eyelids
- Effect of Contact Lenses or Solutions
- Iatrogenic (Oral or Local Medication)
- Foreign Body (Though Usually Presents with Pain and Redness)
Rare Diagnoses
- Pubic Lice (Can Affect Eyelashes)
- Floppy Eyelid Syndrome (Chronic Conjunctivitis with Lax Eyelids in Obese, Middle-Aged Men)
- Sebaceous Gland Carcinoma
- Thyroid Eye Disease
Ready reckoner
Key distinguishing features of the most common diagnoses
| Allergic Conjunctivitis | Infective Conjunctivitis | Dry Eyes | Blepharitis | Blocked Tear Duct | |
|---|---|---|---|---|---|
| Bilateral | Yes | Possible | Yes | Yes | Possible |
| Eyes Red | Yes | Yes | Possible | No | No |
| Eyelids Red | Possible | No | No | Yes | No |
| Seasonal | Possible | No | No | No | No |
| Discharge | Yes | Yes | Possible | No | Yes |
Possible investigations
Likely: None.
Possible: Swab, Schirmer’s test.
Small Print: TFT, thyroid autoantibodies, MRI orbits, biopsy.
- Swab: May be necessary in persistent discharge; essential in neonates who’ve had sticky eyes since birth.
- Schirmer’s test: To assess for dry eye – may be performed by the optician.
- TFT, thyroid autoantibodies, MRI orbits – may be required in suspected thyroid eye disease.
- Biopsy: Rarely, if sebaceous gland carcinoma suspected.
Top Tips
- Diagnosis can be difficult and an optician’s input may be invaluable.
- Enquire about the use of OTC drops and their effect: This may give clues to the underlying problem. Sometimes, the drops themselves may be the cause.
- It can be easy to overlook entropion – ask the patient to squeeze the eyes shut, then suddenly open them, in which case a subtle entropion should be revealed.
- Bear in mind that patients with dry eyes sometimes paradoxically complain of a stringy discharge.
Red Flags
- Remember that thyroid eye disease can present before biochemical dysfunction – if in doubt, refer.
- Do not overlook a foreign body as a possible cause, especially if the history is vague and the symptoms unilateral.
- Chlamydia and gonorrhoea must be excluded in the neonate with a sticky eye or eyes from birth.
- The rare sebaceous gland carcinoma causes blepharitis-type symptoms, but with localised inflammation and localised loss of lashes.