<unk>  is a sexually transmitted disease caused by Haemophilus ducreyi, a fastidious Gram-negative coccobacillus. There are 3 classes of this bacteria, 2 of which cause genital ulcer disease and 1 that may be the cause of cutaneous limb ulcers. Pathogenesis involves secretion of 2 virulence factors: fimbrialike proteins (Flp) responsible for adhesion and H. ducreyi cytolethal distending toxin (HdCDT) which cause DNA double-stranded breaks that lead to cell cycle arrest and apoptosis in epithelial cells, fibroblasts, and lymphocytes.<unk>  must be differentiated from other diseases that cause genital ulcers and lymphadenopathy including syphilis, herpes simplex, dermatologic aspects of Behçet's disease, dermatologic manifestations of Lymphogranuloma venereum, donovanosis, and fixed drug eruption. The characteristic manifestation of<unk>  is a painful, nonindurated ulcer. The ulcer looks similar to a syphilitic chancre. Approximately 50% of patients (predominantly in males) develop painful inguinal lymphadenopathy, known as buboes.<unk>  can be classified according to its clinical variants identified during a physical examination. Such variants include: dwarf, giant, follicular, transient, serpiginous, mixed, and phagedenic.<unk>  symptoms typically develop 4 to 10 days after infection. Lack of rapid and reliable laboratory tests make diagnosis and treatment decisions based on microbiologic findings difficult. Available laboratory tests involve acquiring a sample of ulcer exudate and include: Gram stain, culture, and multiplex Polymerase Chain Reaction (M-PCR). UNAIDS and the World Health Organization estimate the global incidence of<unk>  to be approximately 6 million cases per year.<unk>  is a common cause of genital ulcer disease in developing countries, and is also prevalent in areas of crack cocaine use and prostitution in developed countries. The mainstay of therapy for<unk>  is antimicrobial therapy with a single dose of Azithromycin or Ceftriaxone. Special considerations must be taken with patients who are HIV positive or with women who are pregnant or breastfeeding. Methods of primary prevention include: limiting the number of sexual partners, especially those who are prostitutes, using a barrier method of contraception, avoiding traveling to endemic areas of<unk>  and prophylaxis with azithromycin. The goal of secondary prevention is to stop the spread of disease. Therefore infection individuals should abstain from sexual intercourse until symptoms reside.
Chancroid
Tinea manuum
Larva migrans
Tinea
Scrofula
Tinea faciei
Tinea capitis
Trichinosis