Skip to main content

Military Health System

Test of Sitewide Banner

This is a test of the sitewide banner capability. In the case of an emergency, site visitors would be able to visit the news page for addition information.

Brief Review: Clinical and Epidemiologic Characteristics of Genital Skin Lesions Due to Infectious Causes

Image of Brief Review: Clinical and Epidemiologic Characteristics of Genital Skin Lesions Due to Infectious Causes. Brief Review: Clinical and Epidemiologic Characteristics of Genital Skin Lesions Due to Infectious Causes


During the current global mpox outbreak, many cases have presented atypically with skin lesions localized to the genital and perianal areas.1,2 The rash associated with mpox can be confused, or occur concurrently, with various sexually transmitted infections. The following text and Table provide a brief comparison of mpox characteristics to those of other infectious causes of genital skin lesions.


Literature from 2 textbooks, Genital Ulcer Adenopathy Syndrome and Hunter's Tropical Medicine and Emerging Infectious Diseases, were reviewed and summarized to compare clinical aspects of infectious disease skin lesions to include: incubation period, lesion characteristics (i.e., type, number, progression pattern, border, depth, induration), and presence of pain or lymphadenopathy.3,4 Mpox skin lesion features recorded in historical and current outbreaks were incorporated as well. Additionally, U.S. and military disease rates (where available) were added to provide epidemiologic context for the frequency of these infectious diseases.



Mpox classically presents with fever, myalgia, and lymphadenopathy, followed 1-3 days later by a centrifugal rash that starts on the face and extremities and then disseminates across the body. In the current outbreak, however, early lesions have often been localized to the genital and perineal/perianal areas because of close sexual or intimate contact.1,2 The incubation period is 6-13 days, and lesions typically evolve synchronously through four stages—-mac­ular, papular, vesicular, to pustular—-before scabbing and resolving over the subsequent 2-4 weeks. The 2-10 mm lesions usually are painful, firm, well-circumscribed, and centrally umbilicated.5 

Herpes simplex virus

In the U.S., herpes simplex virus (HSV-1 or HSV-2) is the most common cause of genital ulcers, affecting 5.6% of the U.S. adult population, with over half a million new cases annually.6 Among active component service members, the incidence rate of HSV infections from 2013 through 2021 was 23.3 cases per 10,000 person-years (p-yrs), and the rate was 4.5 times higher in females (68.0 cases per 10,000 p-yrs) compared to males.7 The incubation period is 2-12 days, and herpetic lesions begin as a cluster of multiple, 2-4 mm vesicles with an underlying erythematous base. These fragile lesions rupture, progressing to painful erosions and shallow ulcerations that gradually heal over 4-10 days. 


Syphilis, caused by the bacterium Treponema pallidum, is the second most common cause of genital ulcers in the U.S.7 Among active component service members, the incidence rate of syphilis was 5.0 cases per 10,000 p-yrs from 2013 through 2021.8 The primary syphilis lesion (chancre) begins as a solitary, firm papule that quickly becomes a painless ulcer with well-defined margins and indurated base. The incubation period is 10-90 days, and the ulcer heals spontaneously within 3-6 weeks. Although the maculopapular rash associated with secondary syphilis usually appears 4-10 weeks after the primary chancre, primary and secondary syphilis findings overlap in 15% of cases.9  


The gram-negative bacterium Haemophilus ducreyi causes chancroid, which is rarely diagnosed in the U.S., with less than 10 cases reported annually.10 Sporadic outbreaks occur in Africa and the Caribbean.9,11 The incubation period is 4-10 days, and begins as an erythematous papule that rapidly evolves into a pustule and erodes into a deep ulcer.  These painful 1-2 cm ulcers have clearly demarcated borders with a friable base covered by a gray or yellow exudate. It is common to have multiple ulcers.

Lymphogranuloma venereum (LGV)

LGV is predominantly found in tropical or subtropical regions, but outbreaks have been reported among men who have sex with men in Europe, North America, and Australia.12,13 The true incidence rate of this bacterial infection in the U.S. and among service members is unknown because national reporting of LGV ended in 1995. LGV is caused by Chlamydia trachomatis serovars L1, L2, or L3. A 2011 report of surveillance data from multiple sites in the U.S. found that less than 1% of rectal swabs obtained from military service members positive for Chlamydia trachomatis were positive for LGV serovars.14 LGV infection has 3 stages: ulceration, regional lymphadenopathy, anogenital fibrosis. The incubation period is 3-12 days, and the primary stage of LGV is characterized by small, painless genital papules or ulcers that heal spontaneously within a few days. 

Granuloma inguinale (Donovanosis)

Donovanosis is a rare disease caused by the intracellular bacterium Klebsiella granulomatis and is sporadically found in Asia, South Africa, and South America.9 In a recent MSMR surveillance snapshot on donovanosis among active component service members, only 50 incident cases were identified between 2011 and 2020, with 3-10 cases reported annually.15 It is characterized by painless, progressive ulcers on the genitals or perineum that are highly vascular, have a beefy red appearance, and easily bleed. The incubation period ranges from 1-90 days. 

Varicella-zoster virus (chickenpox/shingles)

The incidence rate of chickenpox infections in the U.S. dramatically decreased following the implementation of the national varicella vaccination program in 1995, with a 97% decline from pre-vaccine years.16 Among active component service members, only 37 confirmed and 205 possible cases were reported between 2016 and 2019.17 Chickenpox presents as multiple red papules in a centripetal distribution, involving the scalp, face, and trunk, then spreading across the body (including the genital area). The incubation period is 14-16 days with prodromal symptoms (fever, headache, malaise, decreased appetite) prior to rash appearance. The itchy lesions progress asynchronously from papules to vesicles (1-4mm) and then rupture and crust or scab over during a final 5-10 days.18 Reactivation of varicella-zoster virus (shingles) presents as multiple, small vesicles in a unilateral dermatomal distribution and may be associated with severe pain, pruritus, and/or burning sensation in the affected dermatome. Vesicles crust over in 7-10 days. 


While mpox is not traditionally known as a sexually transmitted disease, in the current outbreak transmission has primarily been reported with intimate or close sexual contact. This highlights the importance of understanding the differential diagnosis for infectious causes of genital skin lesions, especially in a predominantly young adult military population. Summarizing other infectious diseases provides a framework to more expeditiously diagnose and treat mpox. The table and accompanying text in this article provide a succinct review to compare and contrast these infectious diseases. Additionally, reports of disease rates of each infection provide perspective for the U.S. military population. As the mpox outbreak is new and evolving, case rates are not yet well described. Infectious genital skin lesions and other sexually transmitted infections may occur concurrently, thus testing for co-infections is important to quickly identify all pathogens and appropriately treat individuals.


The contents described in this publication are those of the authors and do not necessarily reflect official policy or position of Uniformed Services University of the Health Sciences, the Department of Defense, or the Department of the Air Force.

Author affiliations

Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland (Lt Col Hsu); Air Force Medical Readiness Agency, Falls Church, VA (Lt Col Sayers).


  1. Minhaj FS, Ogale YP, Whitehill F, et al. Monkeypox outbreak—-nine states, May 2022. MMWR. 2022;71(23):764-769.
  2. Thornhill JP, Barkati S, Walmsley S, et al. Monkeypox virus infection in humans across 16 countries—-April–June 2022. N Engl J Med. 2022:387:679-691.  
  3. Kraus SJ. Genital ulcer adenopathy syndrome. In: Holmes KK, Mardh PA, Sparling PF, Wiesner PJ, eds. Sexually Transmitted Diseases. New York, McGraw-Hill; 1984:706-714.
  4. Magill, AJ, Ryan ET, Hill DR. Hunter's Tropical Medicine and Emerging Infectious Disease: Expert Consult—-Online and Print. Elsevier Health Sciences, 2012. 
  5. Macneil A, Reynolds MG, Braden Z, et al. Transmission of atypical varicella-zoster virus infections involving palm and sole manifestations in an area with monkeypox endemicity. Clin Infect Dis. 2009;48(1):e6-e8. doi:10.1086/595552
  6. Kreisel KM, Spicknall IH, Gargano JW, et al. Sexually transmitted infections among U.S. women and men: prevalence and incidence estimates, 2018. Sex Transm Dis. 2021;48(4):208-214. doi:10.1097/OLQ.0000000000001355
  7. Roett MA, Mayor MT, Uduhiri KA. Diagnosis and management of genital ulcers. Am Fam Physician. 2012:85(3):254-262.
  8. Armed Forces Health Surveillance Department. Update: sexually transmitted infections, active component, U.S. Armed Forces, 2012-2020. MSMR. 2021;28(3):13-22
  9. Dombrowski JC, Celum C, Baeten J. Chapter 43: Syphilis. In: Sanford CA, Pottinger PS, Jong EC, eds. The Travel and Tropical Medicine Manual. 5th ed. Elsevier; 2017:535-544.
  10. Centers for Disease Control and Prevention. Table 43. Chancroid--Reported Cases and Rates of Reported Cases by State/Territory in Alphabetical Order, United States, 2015-2019. Published April 12, 2022. Accessed July 29, 2022. 
  11. Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep 2021;70(4):1-187. doi: 10.15585/mmwr.rr7004a1. 
  12. de Voux A, Kent JB, Macomber K, et al. Notes from the field: cluster of lymphogranuloma venereum cases among men who have sex with men--Michigan, August 2015–April 2016. MMWR. 2016;65:920–921. doi: 
  13. Simms I, Ward H, Martin I, Alexander S, Ison C. Lymphogranuloma venereum in Australia. Sex Health. 2006;3(3):131-133. doi:10.1071/sh06039
  14. Hardick J, Quinn N, Eshelman S, et al. O3-S6.04 Multi-site screening for lymphogranuloma venereum (LGV) in the USA. Sex Transm Infect. 2011;87(Suppl 1):A82-A82. doi:10.1136/sex­trans-2011-050109.136
  15. Daniele D, Wilkerson T. Surveillance snapshot: donovanosis among active component service members, U.S. Armed Forces, 2011-2020. MSMR. 2021;28(12):22.
  16. Lopez A, Harrington T, Marin M. Chapter 22: Varicella. U.S. Department of Health and Hu­man Services. Epidemiology and Prevention of Vaccine-Preventable Diseases, 14th ed. Published September 20, 2021. Accessed September 3, 2022. 
  17. Williams VF, Stahlman S, Fan M. Measles, mumps, rubella, and varicella among service members and other beneficiaries of the Military Health System, 1 January 2016–30 June 2019. MSMR. 2019;26(10):2-12.
  18. Hall E, Wodi A P, Hamborsky J., et al., eds. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. 14th ed. Washington, DC, Public Health Foundation, 2021.

TABLE. Differential Diagnosis of Genital Ulcers/Lesions

You also may be interested in...

Sep 1, 2022

Brief Report: Menstrual Suppression Among U.S. Female Service Members in the Millennium Cohort Study

U.S. Marine Corps Lance Cpl. Bobby Brodeur, a Gilford, New Hampshire, native and machine gunner with 3rd Battalion, 6th Marine Regiment, 2d Marine Division, conducts gun drills at Camp Lejeune, North Carolina, Oct. 13, 2022. Brodeur is currently serving as a machine gunner with 3/6 and is one of three female infantry Marines in Kilo Co. She has demonstrated an unwavering commitment to 3/6 through her high physical fitness scores and leading by example within the platoon. (U.S. Marine Corps photo by Lance Cpl. Megan Ozaki)

Menstrual suppression allows for the control or complete suppression of menstrual periods through hormonal contraceptive methods. In addition to preventing pregnancy, suppression can alleviate medical conditions and symptoms associated with menstruation such as iron deficiency anemia,1 eliminate logistical hygiene-related challenges, and improve ...

Sep 1, 2022

MSMR Vol. 29 No. 09 - September 2022

.PDF | 2.12 MB

A monthly publication of the Armed Forces Health Surveillance Division. This issue of the peer-reviewed journal contains the following articles: Surveillance trends for SARS-CoV-2 and other respiratory pathogens among U.S. Military Health System Beneficiaries, Sept. 27, 2020 – Oct. 2,2021; Establishment of SARS-CoV-2 genomic surveillance within the ...

Aug 1, 2022

Brief Report: Pain and Post-Traumatic Stress Disorder Screening Outcomes Among Military Personnel Injured During Combat Deployment.

U.S. Air Force Airman 1st Class Miranda Lugo, right, 18th Operational Medical Readiness Squadron mental health technician and Guardian Wingman trainer, and Maj. Joanna Ho, left, 18th OMRS director of psychological health, discuss the suicide prevention training program, Guardian Wingman, at Kadena Air Base, Japan, Aug. 20, 2021. Guardian Wingman aims to promote wingman culture and early help-seeking behavior. (U.S. Air Force photo by Airman 1st Class Anna Nolte)

The post-9/11 U.S. military conflicts in Iraq and Afghanistan lasted over a decade and yielded the most combat casualties since the Vietnam War. While patient survivability increased to the high­est level in history, a changing epidemiology of combat injuries emerged whereby focus shifted to addressing an array of long-term sequelae, including ...

Aug 1, 2022

Musculoskeletal Injuries During U.S. Air Force Special Warfare Training Assessment and Selection, Fiscal Years 2019–2021.

U.S. Air Force Capt. Hopkins, 351st Special Warfare Training Squadron, Instructor Flight commander and Chief Combat Rescue Officer (CRO) instructor, conducts a military free fall equipment jump from a DHC-4 Caribou aircraft in Coolidge, Arizona, July 17, 2021. Hopkins is recognized as the 2020 USAF Special Warfare Instructor Company Grade Officer of the Year for his outstanding achievement from January 1 to December 31, 2020.

Musculoskeletal (MSK) injuries are costly and the leading cause of medical visits and disability in the U.S. military.1,2 Within training envi­ronments, MSK injuries may lead to a loss of training, deferment to a future class, or voluntary disenrollment from a training pipeline, all of which are impediments to maintaining full levels of manpower and ...

Aug 1, 2022

MSMR Vol. 29 No. 08 - August 2022

.PDF | 822.83 KB

A monthly publication of the Armed Forces Health Surveillance Division. This issue of the peer-reviewed journal contains the following articles: Surveillance trends for SARS-CoV-2 and other respiratory pathogens among U.S. Military Health System Beneficiaries, Sept. 27, 2020 – Oct. 2,2021; Establishment of SARS-CoV-2 genomic surveillance within the ...

Jul 1, 2022

Establishment of SARS-CoV-2 Genomic Surveillance Within the Military Health System During 1 March–31 December 2020.

Dr. Peter Larson loads an Oxford Nanopore MinION sequencer in support of COVID-19 sequencing assay development at the U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland. (Photo by John Braun Jr., USAMRIID.)

This report describes SARS-CoV-2 genomic surveillance conducted by the Department of Defense (DOD) Global Emerging Infections Surveillance Branch and the Next-Generation Sequencing and Bioinformatics Consortium (NGSBC) in response to the COVID-19 pandemic. Samples and sequence data were from SARS-CoV-2 infections occurring among Military Health System ...

Jul 1, 2022

Brief Report: Phase I Results Using the Virtual Pooled Registry Cancer Linkage System (VPR-CLS) for Military Cancer Surveillance.

A patient at Naval Hospital Pensacola prepares to have a low-dose computed tomography test done to screen for lung cancer. Lung cancer is the leading cause of cancer-related deaths among men and women. Early detection can lower the risk of dying from this disease. (U.S. Navy photo by Jason Bortz)

The Armed Forces Health Surveillance Division, as part of its surveillance mission, periodically conducts studies of cancer incidence among U.S. military service members. However, service members are likely lost to follow-up from the Department of Defense cancer registry and Military Health System data sets after leaving service and during periods of ...

Jul 1, 2022

Surveillance Trends for SARS-CoV-2 and Other Respiratory Pathogens Among U.S. Military Health System Beneficiaries, 27 September 2020–2 October 2021.

Staff Sgt. Misty Poitra and Senior Airman Chris Cornette, 119th Medical Group, collect throat swabs during voluntary COVID-19 rapid drive-thru testing for members of the community while North Dakota Army National Guard Soldiers gather test-subject data in the parking lot of the FargoDome in Fargo, N.D., May 3, 2020. The guardsmen partnered with the N.D. Department of Health and other civilian agencies in the mass-testing efforts of community volunteers. (U.S. Air National Guard photo by Chief Master Sgt. David H. Lipp)

Respiratory pathogens, such as influenza and adenovirus, have been the main focus of the Department of Defense Global Respiratory Pathogen Surveillance Program (DoDGRPSP) since 1976.1. However, DoDGRPSP also began focusing on SARS-CoV-2 when COVID-19 was declared a pandemic illness in early March 2020.2. Following this declaration, the DOD quickly ...

Jul 1, 2022

Suicide Behavior Among Heterosexual, Lesbian/Gay, and Bisexual Active Component Service Members in the U.S. Armed Forces.

  The DOD’s theme for National Suicide Prevention Month is “Connect to Protect: Support is Within Reach.” Deployments, COVID-19 restrictions, and the upcoming winter season are all stressors and potential causes for depression that could lead to suicidal ideations. Options are available to individuals who are having thoughts of suicide and those around them (Photo by Kirk Frady, Regional Health Command Europe).

Lesbian, gay, and bisexual (LGB) individuals are at a particularly high risk for suicidal behavior in the general population of the United States. This study aims to determine if there are differences in the frequency of lifetime suicide ideation and suicide attempts between heterosexual, lesbian/gay, and bisexual service members in the active ...

Jul 1, 2022

MSMR Vol. 29 No. 07 - July 2022

.PDF | 1.67 MB

A monthly publication of the Armed Forces Health Surveillance Division. This issue of the peer-reviewed journal contains the following articles: Surveillance trends for SARS-CoV-2 and other respiratory pathogens among U.S. Military Health System Beneficiaries, Sept. 27, 2020 – Oct. 2,2021; Establishment of SARS-CoV-2 genomic surveillance within the ...

Jun 1, 2022

Absolute and Relative Morbidity Burdens Attributable to Various Illnesses and Injuries, Active Component, U.S. Armed Forces, 2021

In 2021, as in prior years, the medical conditions associated with the most medical encounters, the largest number of affected service members, and the greatest number of hospital days were in the major categories of injuries, musculoskeletal disorders, and mental health disorders. Despite the pandemic, COVID-19 accounted for less than 2% of total ...

Jun 1, 2022

Morbidity Burdens Attributable to Various Illnesses and Injuries, Deployed Active and Reserve Component Service Members, U.S. Armed Forces, 2021

As in previous years, among service members deployed during 2021, injury/poisoning, musculoskeletal diseases and signs/symptoms accounted for more than half of the total health care burden during deployment. Compared to garrison disease burden, deployed service members had relatively higher proportions of encounters for respiratory infections, skin ...

Jun 1, 2022

Hospitalizations, Active Component, U.S. Armed Forces, 2021

The hospitalization rate in 2021 was 48.0 per 1,000 person-years (p-yrs), the second lowest rate of the most recent 10 years. For hospitalizations limited to military facilities, the rate in 2021 was the lowest for the entire period. As in prior years, the majority (71.2%) of hospitalizations were associated with diagnoses in the categories of mental ...

Refine your search
Last Updated: July 11, 2023
Follow us on Instagram Follow us on LinkedIn Follow us on Facebook Follow us on Twitter Follow us on YouTube Sign up on GovDelivery