A few months ago, American Family Physician published a nice review article on the diagnosis and management of genital ulcers. How do you remember the classic appearances of the lesions? I often quickly check references to confirm my suspicions.
I find the two following tables helpful to remember. The table of differential diagnoses is from AFP. The article also reviews the confirmatory diagnostic testing and treatment protocols. The table of the clinical characteristics for the main infectious causes is from "The Practitioner’s Handbook for the Management of Sexually Transmitted Disease".
Note: Although the primary lesion from Lymphogranuloma venereum (LGV) can have a variable appearance the tender, and often suppurative lymphadenopathy (buboes) are classic.
Feel free to download this card and print on a 4'' x 6'' index card.
Images from "The Practitioner’s Handbook for the Management of Sexually Transmitted Disease", sponsored by the CDC (4th edition, 2007) can be found here:
Most recent 2010 CDC treatment guidelines:
Roett MA, Mayor MT, Uduhiri KA. Diagnosis and management of genital ulcers. Am Fam Physician. 2012; 85(3):254-262. .