Education

ANSWER

From questions on page 616

(1) What is the diagnosis based on skin and conjunctival biopsies (fig 2)?

Histopathology of conjunctival and skin biopsies revealed granulomatous infiltrate with epithelioid cells, Langhans giant cells but no caseation necrosis and no acid fast bacilli on Ziehl–Nelson staining. Moreover, bacterial culture from skin and conjunctiva showed growth with a protein chain reaction positive test for Mycobacterium tuberculosis. Thus a diagnosis of lupus vulgaris with chronic cicatrising conjunctivitis was made.

We note that if a presumptive diagnosis of tuberculosis is commonly based on the finding of acid fast bacilli during microscopic examination of a diagnostic specimen, the definitive diagnosis is indeed dependent either on a positive culture for Mycobacterium tuberculosis, which is both cumbersome and time consuming or, recently, on amplification and detection of its specific DNA by polymerase chain reaction.

(2) How would you manage this patient?

Tuberculosis produces foci of granulomatous inflammation, usually in the lungs, but can involve practically …