The diagnosis usually is made serologically (through complement fixation) and by exclusion of other causes of inguinal lymphadenopathy or genital ulcers. Serologic testing has a sensitivity of 80% after two weeks. Serologic testing may not be specific for serotype (has some cross reactivity with other chlamydia species) and can suggest<unk>  from other forms because of their difference in dilution, 1:64 more likely to be<unk>  and lower than 1:16 is likely to be other chlamydia forms (emedicine). For identification of serotypes, culture is often used. Culture is difficult. Requiring a special medium, cycloheximide-treated McCoy or HeLa cells, and yields are still only 30-50%. DFA, or direct fluorescent antibody test, PCR of likely infected areas and pus, are also sometimes used. DFA test for the L-type serovar of C. trachomatis is the most sensitive and specific test, but is not readily available. If polymerase chain reaction (PCR) tests on infected material are positive, subsequent restriction endonuclease pattern analysis of the amplified outer membrane protein A gene can be done to determine the genotype. Recently a fast realtime PCR (TaqMan analysis) has been developed to diagnose<unk> . With this method an accurate diagnosis is feasible within a day. It has been noted that one type of testing may not be thorough enough.
Lymphogranuloma venereum
Cat-scratch disease
Tuberculosis cutis orificialis
Granuloma faciale
Tuberculosis verrucosa cutis
Ichthyosis bullosa of Siemens
Granulosis rubra nasi
Demodicosis