Answer

Chancroid (soft chancre)

(Haemophilus ducreyi)

A 24 year old man who recently immigrated from Cuba comes into the family practice clinic complaining of soft, painful lesions. They are nonindurated with pus and erythema. Inguinal lymphadenopathy is present.

Labs: Gram-negative rods (isolated from pus aspirated from a lymph node or lesion) grow on blood agar supplemented with X (heme) factor but not V (NAD) factor.

Discussion: The diagnosis is Chancroid caused by Haemophilus ducreyi. It is a sexually transmitted disease. Diagnosis is made by isolating the organism. In addition to the clinical picture above, there may also be pus, suppuration, and a necrotic exudate present. Unlike Haemophilus influenzae, Haemophilus ducreyi does not require V factor. It is uncommon in the U.S.

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