Question

All statements are true about trachoma except:

• A. Trachoma is caused by a bedsonian organism of the psittacosis-lymphogranuloma-trachoma (PLT) group.
• B. Strains mainly responsible are A, B, Ba and C.
• C. Marked papillary hyperplasia with limbal follicles is seen in stage III.
• D. Corneal ulceration is a complication.

Hint:

Stage III in McCallan staging is the scarring stage, not the active follicular stage.

Answer 1

The Correct Option is C

Step 1: Trachoma is caused by Chlamydia trachomatis, a bedsonian (obligate intracellular) organism of the psittacosis-lymphogranuloma-trachoma (PLT) group, so statement a is true.

Step 2: Serotypes A, B, Ba and C cause hyperendemic blinding trachoma, while serotypes D to K cause oculogenital paratrachoma. Hence statement b is true.

Step 3: By McCallan's classification, stage III is the cicatrising stage marked by scarring of the palpebral conjunctiva, not by active papillary hyperplasia or limbal follicles. Follicles and papillae are features of the early active stages (I and II), so statement c is the false one.

Step 4: Corneal ulceration can occur from trachomatous pannus and trichiasis, so statement d is true. The exception is therefore statement c.