STIs (Sexually transmitted infections) are a category of infectious diseases, whose main mode of transmission consists of intimate sexual activity involving moist mucosal membranes of the penis, vulva, vagina, cervix, anus, rectum, mouth, and pharynx, and their surfaces adjacent to their skin. A variety of infections, including syphilis, gonorrhea, human virus immunodeficiency (HIV), herpes genitals, genital warts, chlamydia and trichomoniasis, can be sexually transmitted. Bacterial vaginosis and genital candidiasis are not considered STIs, but in sexually active women they are common causes of vaginal discharge. Chancroid, venereal lymphogranuloma (LGV) and inguinal granuloma are commonly seen in tropical countries. In tropical countries, Hepatitis A, B, C and D can be sexually and in other ways acquired.



Sexually transmitted infections (STIs) are classified into two main groups.

 Towards bacterial sexually transmitted infections

  • Chancroid
  • Gonorrhea
  • LGV
  • Infection with chlamydial
  • Inguinal granuloma

The viral sexually transmitted infections

  • Anogenital warts
  • Human papillomavirus
  • Hepatitis viral
  • Simplex genital herpes
  • Molluscum infectious



Discharge from Urethral: Gonorrhea and chlamydia are the main causes of urethral discharge. Tests for both of these infections in a significant minority are negative, a scenario often referred to as non-specific urethritis (NSU).

Itching and/or rash genital: Patients may have many combinations of penile/genital symptoms. Balanitis refers to glans inflammation, often extending down to the bottom of the prepuce, where balanoposthitis is called.

Ulceration of the genital: Genital herpes are the most common cause of ulceration. Typically several painful ulcers affect the gland, penile shaft, or coronal sulcus but rarely occur solitary lesions.

Genital lobsters: The most common cause of genital ‘lumps’ is warts. They are traditionally found in frictional areas during sex, such as paraphernal skin and penis prepuce. Warts can also be seen in urethral meat, less often on the shaft or on the base of the penis. Perianal warts in men who do not have anal sex are surprisingly common.

Men who have sex with men have proclitis: Gonorrhea, syphilis, herpes and chlamydia are STIs that can cause proctitis in MSM. Chlamydia trachomatis substrains which cause LGV (L1-3) were associated with severe proctitis outbreaks in Northern Europe, including the United Kingdom. Symptoms include mucopurulent anal fluid, pain, rectal fluid, and tenesmus. Mucopus and erythema with contact bleeding may be shown.



Discharge of the vagina: Natural vaginal discharge can vary significantly, particularly under different hormonal influences like pregnancy, prescribed contraception, or puberty. A sudden or recent flux change, particularly when associated with colour and/or smell alterations, or vulval itch/irritation, is more likely to show an infective cause than gradual or prolonged changes. Worldwide, trichomoniasis is the most common treatable STI that causes vaginal discharge. Gonorrhea and chlamydia are other possibilities. HSV may cause increased discharge, although the predominant symptoms are vulval pain and dysuria.

Pain in the lower abdomen: Pelvic inflammatory disease (PID, fallopian tube infection or inflammation and surrounding structures) is part of the wide-ranging differential diagnosis in women, in particular those sexually active, for lower abdominal pain. Pelvic inflammatory disease (PID) is more likely if there is dyspareunia, abnormal vaginal discharge and/or bleeding in addition to acute/sub-acute pain. Systemic features such as fever and malaise can also be present. Usually, the lower abdominal pain is bilateral and vaginal examination shows adnexal sensitivity with or without cervical arousal.

Ulceration of the genitals:  Genital herpes are the most common cause of ulceration. Multiple painful ulcers classically affect the introitus, perineum and lips, but solitary lesions rarely occur.


Genital lobsters: Warts are traditionally found in areas of friction during sex, such as the fork and perineum, and are the most common cause of genital lumps. Perianal warts in women with no anal sex are surprisingly common.

Pain and/or itching in Chronic vulval: Women may have a range of chronic, intermittent or continuous symptoms. Current candidiasis can lead to candidate antigen hypersensitivity, with itching and erythema becoming more prominent than increased discharge.


Bacterial sexually transmitted infections

The Syphilis

The syphilis is caused by abrasion in skin or mucous membrane. Adults usually acquired it sexually.

Causative agent:   A spirochete “Traponema palladium”.

Symptoms: Formation of small, firm, painless sores on genitals, anus and mouth, Rashes on body, Fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue.


  • Rapid plasma reagin (RPR),
  • Venereal disease research laboratory (VDRL) test,
  • Traponema antigen-based immuno assay (EIA)


  • Penicillin is drug of choice. A single dose of Benzathine penicillin G (2.4 million units given intramuscularly ) is indicated for early syphilis.
  • Doxycyclin is alternative for patients allergic to penicillin.


 It is the sexually transmitted bacterial infection which involves the columnar epithelium of lower genital tract, rectum, pharynx and eyes.

Causative agent:  Neisseria gonorrhea


In men:

  • Painful urination.
  • Mucopurulent urethral discharge.
  • Swollen testes.

In women:

  • Purulent or mucopurulent vaginal discharge.
  • Painful urination.
  • Post coital bleeding.
  • Inter-menstrual bleeding.
  • Pelvic pain.


  • Culture test (smears taken from urethral or vaginal discharge or pharynx) ,
  • Nucleic acid amplification test (NAAT)


Tab ceftriaxone 500mg Intramuscular injection or ceftriaxone 400mg per oral stat.

Chlamydial Infection

 It is a sexually transmitted disease of milder intensity, mostly asymptomatic.

Causative agent:  Chlamydia trachomatis


In men:

  • Painful urination.
  • Increased urethral discharge in men.
  • Testicular pain.

In women:

  • Increased vaginal discharge.
  • Painful urination.
  • Post coital bleeding.
  • Inter-menstrual bleeding.
  • Pelvic pain.
  • Investigations:
  • Culture test (smears taken from urethra, vagina or cervix ) ,
  • Nucleic acid amplification test (NAAT)
  • Urine complete analysis.


  • Tab Azithromycin 1g orally single dose.


  • Tab Doxycyclin 100mg orally twice daily for 7 days.


The viral sexually transmitted infections

Genital herpes simplex:

Herpes simplex type 1 virus (HSV-1) or type 2 virus (HSV-2) infections creates a wide variety of clinical problems and may facilitate HIV transmission. Infection usually occurs sexually (vaginal, anal, orogenital or oro-anal), but it can also occur perinatal to the neonate. Primary HSV infection, which can be symptomatic or asymptomatic, causes latency in local sensory ganglia. The effect of HSV recurrence is either symptomatic or asymptomatic viral shedding. Usually, the first symptomatic episode is the most serious. HSV-1 is classically linked to orolabial herpes and HSV-2 to anogenital herpes.

Clinical characteristics

The first symptomatic episode presents irritable blades that soon rupture in the external genitalia to form small, tender ulcers. Lesions at other locations may cause dysuria, urethra or vagina discharge (for example, urethra, cervix, perianal, anus or rectum) or anal, perianal and rectal pain. Constitutional symptoms are frequent, including fever, headache and malaise. Extragenital injuries may develop. Sometimes complications are observed, such as urinary retention due to autonomous neuropathy and aseptic meningitis.


Swabs for the detection of PCR of DNA or tissue cultivation are obtained from vesicular fluid or ulcers and typed as either HSV-1 or 2. Type-specific tests for antibodies are available.


First Episode:

We recommend the following 5-day oral regimen

  • 200 mg Aciclovir 5 times a day
  • Famciclovir 250 mg 3 times a day
  • 500 mg of Valaciclovir twice a day.

Analgesia may be necessary and salty bathing may be relaxing.

Recurrent herpes genitals:

Symptomatic recurrences are usually mild and no special treatment other than saline bathing may be required. For more severe episodes, the patient began treatment with oral regimen above 5 days.

Human papillomavirus and warts

Human papillomavirus (HPV) typing DNA has shown over 90 genotypes (pp. 1278), most commonly infecting the genital tract by sexual transmission, including HPV-6, HPV-11, HPV-16 and HPV-18. It is important to distinguish between benign genotypes (HPV-6 and 11), which cause anogenital warts, and genotypes, such as 16 and 18, associated with dysplastic conditions and genital tube cancers but not caused by benign warts.

Clinical characteristics

Anogenital warts caused by HPV may be single or multiple, exophytic, papular or flat. Perianal warts are rare, with local tissue destruction the giant condylloma (Buschke–Löwenstein tumour) develops. Biopsied should be atypical warts. Warts can dramatically increase in size and number during pregnancy, making treatment difficult.


The use of condoms can contribute to preventing transmission. HPV vaccination has been launched and is routine in several countries. Two types of vaccine exist:

  • A bivalent vaccine (Cervarix®) protects against HPV types 16 and 18, which accounts for around 75% of cervical cancers in the United Kingdom.
  • An additional HPV type 6 and 11 protective vaccine (Gardasil®) accounts for over 90% of genital warts.

Various treatments for established diseases are available, including:

  • Podophyllotoxin, 0,5% solution or 0,15% cream (contraindicated in pregnancy) used twice a day during 3 days, then for 4 days off is suitable for the treatment of external warts at home for up to 4 weeks.
  • The cream is also suitable for home-treatment of external warts and is applied three times daily (and washed off after 6–10 hours) for up to 16 weeks.
  • Operational removal.



Molluscum contagiosum

Molluscum contagiosum virus infection, sexual as well as non-sexual

Clinical submission

Flesh-colored hemispheric papules generally have up to 5 mm in diameter after an incubation of 3–12 weeks Lesions are often several and can spread through auto-inoculation once they have been established in a single person. They are found on sexual acquisition on the genitals, lower abdomen and upper thighs. Facial lesions highly suggest that HIV infection is underlying.


Diagnosis is done for clinical reasons.


Therefore, treatment regimens are cosmetic; they include cryotherapy, hyfrecation, topical applications of 0.15% podophyllotoxin (pregnancy) or central expression.

Viral Hepatitis

Hepatitis A–D viruses can be transmitted sexually:

  • Hepatitis A (HAV). Advertising oro-anal sex, digital input, anal intercourse and several sexual partners are linked to HAV transmission in MSM. HAV transmission is also possible in heterosexual men and women through oro-anal sex.
  • Hepatitis B Hepatitis (HBV). Insert oro-anal sex, anal sex and several sex partners are linked to HBV MSM infection. Heterosexual HBV transmission is well documented and commercial sex workers are particularly vulnerable. Hepatitis D (HDV) can also be transmitted sexually.
  • Hepatitis C Hepatitis (HCV). In MSM, but less in heterosexuals, sexual transmission of HCV is well documented. The efficiency of sexual transmission is lower than that of HBV.



Early diagnosis and treatment facilitated by active cases can help reduce infection propagation by limiting infection time and also reduce the risk of re-infection by tracking and treating the sexual partner. It can also be prevented through the use of preventive behaviour.



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  3. McMillan A, Young H, Ogilvie MM, Scott GR. Clinical practice in sexually transmissible infections. London: Saunders; 2002.
  4. Rogstad KE (ed.). ABC of sexually transmitted infections, 6th edn. Oxford: Wiley–Blackwell; 2011.
  5. McMillan A, Scott GR. Sexually transmitted infections: a colour guide. Edinburgh: Churchill Livingstone; 2000; copyright Elsevier.Page 412 insets


Herpes Type 1 Sore On Lip

Examples Of SyphilisIllustration Of PID


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