Question

A man presents with a maculopapular rash two weeks after having a painless genital ulcer. The causative organism of this condition is:

• A. Treponema pallidum
• B. Chlamydia trachomatis
• C. Calymmatobacterium (Klebsiella) granulomatis
• D. Haemophilus ducreyi

Hint:

Painless ulcer then a palm-and-sole rash equals secondary syphilis.

Answer 1

The Correct Option is A

Step 1: Interpret the first lesion. A painless, indurated genital ulcer (chancre) is the primary lesion of syphilis.
Step 2: Interpret the later rash. A widespread maculopapular rash appearing a few weeks after the chancre, classically involving the palms and soles, is secondary syphilis.
Step 3: Identify the organism. Both stages are caused by the spirochaete Treponema pallidum.
Step 4: Exclude the others. Chlamydia trachomatis (LGV) causes a transient painless ulcer with painful buboes but not this rash; Klebsiella granulomatis causes painless beefy-red ulcers of donovanosis without a secondary rash; Haemophilus ducreyi causes a painful ulcer (chancroid), which is the opposite of the painless lesion described.
Conclusion: The painless ulcer followed by a maculopapular rash is syphilis caused by Treponema pallidum. The printed key (A) is medically correct.