Nucleic Acid Amplification Tests (NAAT)
Immunofluorescence
Culture (needle aspiration of bubo)
Serology
Consider anoscopy
Also consider testing for HIV and other possible coinfections
Lymphogranuloma venereum
Chancroid
Tinea capitis
Chlamydia trachomatis
Herpetic whitlow
Granuloma inguinale
Cutaneous larva migrans
Hepatitis B