Allergic (hay fever) conjunctivitis: Hay fever conjunctivitis is usually a reaction to airborne allergens and is mediated by IgE antibodies. The symptomatic hallmark of hay fever conjunctivitis is itching. Typical signs are conjunctival hyperemia, chemosis and mucoid discharge. Attacks are usually short-lived and episodic. Treatment includes cold compresses; topical vasoconstrictors; topical antihistamines, mast cell stabilizers, such as cromolyn sodium or certain non-steroidal anti-inflammatory medications.

Atopic keratoconjunctivitis: Inflammatory keratoconjunctivitis can occur in patients who have, or have had, atopic dermatitis. Patients with this condition often experience ocular itching, photophobia, and watery or mucoid discharge. Ocular signs include small to medium-sized papillae that are equally prominent on the upper and lower palpebral conjunctiva, milky bulbar conjunctival edema, and in severe cases, corneal vascularization and Opacification. Conjunctival scarring can occur and can occasionally lead to symblepharon formation. Patients occasionally develop posterior subcapsular lens opacities or multifaceted or shield-shaped anterior subcapsular lens opacities. Mild cases of atopic keratoconjunctivitis can be successfully managed with topical antihistamine preparations. Patients with moderate to severe disease may respond to topical non-steroidal anti-inflammatory medications, or to agents that inhibit mast cell degranulation. Topical steroids are very effective in reducing external inflammatory symptoms and signs, but they should be reserved for exacerbations with moderate to severe discomfort or associated decreased visual acuity due to corneal involvement.

Vernal keratoconjunctivitis: Vernal keratoconjunctivitis is a seasonally recurring bilateral inflammation of the conjunctiva seen mainly in young males (4 to 16 years of age) with a strong personal or family history of atopy. It is characterized by intense itching, blepharospasm, photophobia, blurred visions, and copious mucoid discharge. Two classic forms of the disease are seen: palpebral vernal and limbal vernal. In palpebral vernal, the inflammation is location predominantly on the palpebral conjunctival surfaces, especially the upper tarsus, where a diffuse papillary hypertrophy develops with giant (cobblestone) papillae.