CHRONIC FOLLICULAR CONJUNCTIVITIS

Chronic follicular conjunctivitis is a mild type of chronic catarrhal conjunctivitis associated with follicular hyperplasia, predominantly
involving the lower lid.

Etiological types
1. Infective chronic follicular conjunctivitis is essentially a condition of 'benign folliculosis' with a superadded mild infection.
Benign folliculosis, also called 'School folliculosis', mainly affects school children. This condition usually occurs as a part of generalized
lymphoid
  hyperplasia of the upper respiratory tract (enlargement of adenoids and tonsils) seen at this age. It may be associated with malnutrition,
constitutional disorders and unhygienic conditions. In this condition, follicles are typically arranged in parallel rows in the lower palpebral conjunctiva
without any associated conjunctival hyperaemia
(Fig.1).

Fig. 1. Benign folliculosis.

2. Toxic type of chronic follicular conjunctivitis is seen in patients suffering from molluscum contagiosum. This follicular conjunctivitis occurs as
a response to toxic cellular debris desquamated into the conjunctival sac from the molluscum contagiosum nodules present on the lid margin (the primary lesion).

3. Chemical chronic follicular conjunctivitis. It is an irritative follicular conjunctival response which occurs after prolonged administration of topical
medication. The common topical preparations associated with chronic follicular conjunctivitis are: idoxuridine (IDU), eserine, pilocarpine, DFP and
adrenaline.

4. Chronic allergic follicular conjunctivitis. A true allergic response is usually papillary. However, a follicular response is also noted in patients with
'contact dermoconjunctivitis'.