Hello everyone !
Here's a way to remember the D/D's of Nodules at the Limbus.
Please Please Please ! Eat Spicy MCDonald's Tortilla.
Please - Pterygium.
Please - Pinguecula.
Please - Phlycten.
Eat - Episcleritis.
Spicy - Scleritis.
M - Melanoma.
C - Choristoma
Donald - Dermoid.
Tortilla - Trachoma. Tranta spots.
1. Out of these Pterygium , Pinguecula and Phlyctens are Conjunctival lesions.
Pterygium is a fold of conjunctiva that encroaches towards the pupil.
It can be vascular and nodule like. Can cause Foreign body sensation and decreased vision if it covers the pupil.
It may also cause Diplopia and a Squint due to its traction over the eye.
A pinguecula is milky like nodular swelling of the conjunctiva.
A Phlycten is a lesion in Phlyctenular Conjunctivitis which is an allergic or Hypersensitivity response to Tuberculin or staph Antigens. There is intense itching , discharge and nodules in the eye - called Phlyctens.
2. The lesions of Episcleritis and Scleritis are similar. They're both associated with systemic disease like Rheumatoid Arthritis , SLE, Sarcoidosis etc.
Scleritis is a more severe one of the two. There's marked redness and congestion of the eye along with multiple vascular nodules. The eye is very inflamed. There is intense pain and watering. It needs urgent treatment. It may causes various types of staphylomas.
Episcleritis is a more benign form. There is intense itching , nodular vascularity and discharge with some amount of congestion.
3. Tumors like Choristoma , Dermoid tumor and Melanoma mainly arise from the uvea. They're not very common.
4. Trachoma : presence of lesions in trachoma at the nodule may be prominent. You may also get 'Horner Tranta spots' in Vernal Keratoconjunctivitis which is an allergic Conjunctivitis.
Hope this helped !
Stay awesome !