Merck Manual

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Granuloma Inguinale



Sheldon R. Morris

, MD, MPH, University of California San Diego

Reviewed/Revised Feb 2023

Granuloma inguinale is a sexually transmitted infection caused by the bacteria Klebsiella granulomatis. It leads to chronic inflammation and scarring of the genitals.

  • Granuloma inguinale typically causes a painless, red lump on or near the genitals, which slowly enlarges, then breaks down to form a sore.

  • Doctors suspect the infection if people have typical symptoms and live in areas where the infection occurs, and doctors confirm the diagnosis by examining a sample of fluid scraped from the sore.

  • Treatment with antibiotics is usually effective.

  • Using condoms during genital sex can help prevent passing granuloma inguinale and other sexually transmitted infections (STIs) from one person to another.

Granuloma inguinale is extremely rare in high-resource countries but occurs in Papua New Guinea, Australia, southern Africa, the Caribbean, and parts of Brazil and India.

Symptoms of Granuloma Inguinale

Symptoms of granuloma inguinale usually begin 1 to 12 weeks after infection. The first symptom is a painless, red nodule that slowly enlarges into a round, raised lump. The lump then breaks down to form a foul-smelling sore near the site of the initial infection:

  • Penis, scrotum, groin, and thighs in men

  • Vulva, vagina, and surrounding skin in women

  • Face

  • Anus and buttocks in people who have anal intercourse

The sores slowly enlarge and spread to nearby tissue, causing further damage. Sores may also spread when they come into contact with other areas of the body. Without treatment, the sores continue to spread.

Sores heal slowly and may result in permanent scarring.

Occasionally the infection spreads through the bloodstream to the bones, joints, or liver.

Diagnosis of Granuloma Inguinale

  • Examination of fluid from the sore

Granuloma inguinale is suspected in people who live in areas where the infection is more common and who have sores typical of the infection.

To confirm the diagnosis of granuloma inguinale, doctors take a sample of fluid scraped from the sore and examine it under a microscope.

If the diagnosis is unclear, doctors take a sample of tissue and examine it under a microscope (biopsy).

Treatment of Granuloma Inguinale

  • An antibiotic

  • Testing and treatment of sex partners

Treatment is with the antibiotic azithromycin taken by mouth for at least 3 weeks.

The antibiotics trimethoprim-sulfamethoxazole, doxycycline, erythromycin, and ciprofloxacin are alternative treatments. Sometimes antibiotics are given by injection into a muscle or vein.

When treated, people usually begin to improve within 7 days. Healing may be slow and sores may recur. Then, treatment is required for a longer time. After treatment appears successful, people should be checked periodically for 6 months.

Current sex partners should be examined and, if infected, treated.

Prevention of Granuloma Inguinale

The following general measures can help prevent granuloma inguinale (and other sexually transmitted infections):

Drugs Mentioned In This Article

Generic Name Select Brand Names
Azasite, Zithromax, Zithromax Powder, Zithromax Single-Dose , Zithromax Tri-Pak, Zithromax Z-Pak, Zmax, Zmax Pediatric
Primsol, Proloprim, TRIMPEX
Acticlate, Adoxa, Adoxa Pak, Avidoxy, Doryx, Doxal, Doxy 100, LYMEPAK, Mondoxyne NL, Monodox, Morgidox 1x, Morgidox 2x , Okebo, Oracea, Oraxyl, Periostat, TARGADOX, Vibramycin, Vibra-Tabs
A/T/S, Akne-mycin, E.E.S., Emcin Clear , EMGEL, E-Mycin, ERYC, Erycette, Eryderm , Erygel, Erymax, EryPed, Ery-Tab, Erythra Derm , Erythrocin, Erythrocin Lactobionate, Erythrocin Stearate, Ilosone, Ilotycin, My-E, PCE, PCE Dispertab , Romycin, Staticin, T-Stat
Cetraxal , Ciloxan, Cipro, Cipro XR, OTIPRIO, Proquin XR
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