The regular chlamydial infection is caused by serovars D-K.
Epidemiology
In Europe, the infection is encountered almost only among men who have sex with men.
Several endemic regions exist in the tropics.
Clinical picture and diagnosis
Infection of the lymphatic tissue in the genital region
The incubation period is 1 to 2 weeks.
In Europe, LGV occurs in men as proctitis; inflammatory bowel diseases must be considered in differential diagnosis.
In the classic form, the initial symptom is a painless pustule, which erodes and then heals spontaneously. After a few weeks, inguinal lymph nodes may coalesce to form suppurating buboes.
The clinical picture may be accompanied by urethritis, proctocolitis and, at a later stage, by chronic and constricting fistulas and tight scars.
If LGV is suspected and the nucleic acid test for Chlamydia is positive, the laboratory may be requested to carry out the follow-up test to detect the specific C. trachomatis serovars.
Suspect in a man who has anal sex between men and has proctitis, atypical bowel disease or enlargement of lymph nodes in the anogenital region.
Treatment
Doxycycline 100 mg twice daily for 21 days or erythromycin 500 mg four times daily for 21 days
Report the infection to relevant authorities according to the local regulations.
Test for other STDs.
Trace the infection to identify and treat other infected persons.
Soft chancre (ulcus molle, chancroid)
Causative agent
The gram-negative bacteria Haemophilus ducreyi
Epidemiology
Rare in Europe but encountered in the tropics, e.g. in Africa
Symptoms
Incubation period 3-7 days
One or more tender, eroding genital pustules with an erythematous halo
Unilateral, painful inguinal lymph node enlargements (buboes), which easily erode into suppurating abscesses, are frequent. No systemic infection.
Diagnosis
It is very difficult to culture the bacteria, and the method is not universally available. Detection of the bacteria with a nucleic acid test is available in some European laboratories.
Differential diagnosis must consider syphilis and genital herpes.
Second-line: ciprofloxacin 500 mg twice daily for 3 days or erythromycin 500 mg three to four times daily for 7 days
Granuloma inguinale (donovanosis)
Causative agent
The Gram-negative intracellular bacteria Calymmatobacterium granulomatis
Epidemiology
Very rare; sporadic cases in India, Africa and the West Indian islands
Clinical picture and diagnosis
Incubation period about 50 days
A genital papule which erodes after a few days and increases in size; no lymph gland enlargement
Without treatment the disease progresses to a chronic, granulomatous and tissue-destructing infection.
Extragenital involvement may also occur rarely in donovanosis.
Histology will reveal the presence of Donovan bodies.
Treatment
First-line: azithromycin 1 g per week for 3-4 weeks or until the disease subsides
Alternatively doxycycline 100 mg twice daily or erythromycin 500 mg four times daily (treatment period as above)
References
Lautenschlager S, Kemp M, Christensen JJ, et al. 2017 European guideline for the management of chancroid. Int J STD AIDS 2017;28(4):324--329. [PubMed]
de Vries HJC, de Barbeyrac B, de Vrieze NHN, et al. 2019 European guideline on the management of lymphogranuloma venereum. J Eur Acad Dermatol Venereol 2019;33(10):1821-1828. [PubMed]