What Types of STDs Cause Mouth Sores?

Looking Deeper Into a Mouth Sore

What Types of STDs Cause Mouth Sores?

Issues about sexual health are often misunderstood due to the lack of information disseminated to the public, despite the various efforts made by multiple communities and initiatives to widen the understanding of every individual regarding this topic.

With the resiliency of some individuals in maintaining a somewhat awkward attitude towards such a genuine issue that happens in every human being, it is even harder to penetrate the community with as much information as necessary to prevent injuries and damages to one’s sexual health that could sometimes even be irreversible and fatal.

Another issue that comes to mind when discussing issues about sexual health is the heavy overlap between the manifestations of each condition with other diseases, STD or not. With this, diagnostic procedures are often necessary to provide a more conclusive outlook on what is causing one’s symptoms, bringing us back to the previous issue where sexual health is seen as taboo.

In this case, a mouth sore is one of the symptoms that is commonly seen as an oral manifestation of STDs while likewise being a telltale sign of other non-STD diseases involving the oral cavity. Although it is effortless to spot the presentation, providing a differential diagnosis with a physical examination alone would be more than inaccurate for many – leading to various errors and causing more harm than good to the unknowing public.

To aid this, it is efficient to know that even though this particular manifestation exudes vagueness from the get-go, looking at its accompanying symptoms and other potential risk factors could help one provide a more accurate explanation for such a manifestation – allowing you to procure the necessary tests or contact the appropriate professionals who could further help you out with your condition. While this might not necessarily provide you a conclusive diagnosis every time you present with mouth sores, it does go a long way in ensuring that you are not stuck between the options of having anything to do about it or approaching it incorrectly only to fail in the end.

Mouth Sores: What is it?

Mouth sores are essentially familiar to everyone due to how ordinary their existence is in various conditions – infectious or not, sexually transmitted or not. Mouth sores are common manifestations that often present as a shallow cavity on the soft tissues of your mouth, such as your lips, cheeks, gums, tongue, and even on the floor and roof of your mouth. Some of these presentations are caused by an irritant that you have been exposed to – leading to a breakout that is often resolved by simply distancing yourself from the original cause of the manifestation. However, one should take note and utmost care despite its harmless nature due to how some of these presentations may be caused by something more complex such as an autoimmune condition or even by a pathogen.

Common Co-Existent Symptoms

In most cases of mouth sores, the patient may experience some redness and pain around the area of the blister/sore, especially when eating or drinking foods that could potentially come into contact with the exposed skin. Varying based on its size, severity, and location, mouth sores could even impair one’s ability to eat, swallow, talk, breathe, or drink due to how painful the sore becomes once it comes into contact with any material.

For some instances, mouth sores are often accompanied by the following presentations once the underlying condition starts to progress:

  • Sores larger than half an inch in diameter
  • More consistent sore outbreaks
  • Rash and reddening of the area
  • Joint and muscle pain
  • Fever
  • Diarrhea

You should contact your physician immediately to have yourself tested before your condition causes more complications in this scenario.

Things to Prevent when Mouth Sores are Present

Generally, a patient should remember that contact with virtually anything could aggravate the sores and cause pain and tenderness throughout the affected area. With that in mind, the general recommendations that one might give for an affected individual is to avoid hot, spicy, salty, citrusy, and sugary foods, avoid tobacco and alcohol, and avoid touching, squeezing, or even picking the sores and blisters while the outbreak is still present. Doing so will only aggravate the pain, making its other related symptoms worse in the long run.

In addition to that, one might also gargle with salt water to aid the healing of the sores, eat something cold such as ice pops, sherbet, or shaved ice to help with the pain, and ask their pharmacist about an effective over-the-counter medication that may help provide an initial intervention for your condition. Do note, however, that self-medicating is, as much as possible, discouraged to avoid causing more harm to your body than good. It might be wise to initially approach your doctor first before applying or taking any medication lest it might not be suitable for the actual condition that you should be treating in the first place.

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General Diagnosis of Mouth Sores

The diagnosis of a mouth sore is not necessarily its presence per se but the underlying condition behind this manifestation, especially considering that various conditions contribute to this presentation. In most cases, when you visit your physician complaining of mouth sores, they will be performing a physical examination of your mouth, tongue, and lips, along with a quick medical history taking of your sexual activity and other significant events that might be important in assessing your potential condition. They may then order some pertinent laboratory tests such as biopsies to obtain a more conclusive diagnosis for the condition you are currently struggling with.

Non-STD Causes of Mouth Sores

As previously mentioned, several diseases result in the presentation of mouth sores, particularly those that target the immune system to cause an autoimmune response and those characterized as “infections” due to the presence of a particular pathogen that results in the development of such manifestation.

Oral Lichen Planus

Oral lichen planus is a chronic condition that is often characterized by the presence of mouth sores that are white, lacy, red, swollen, and open, causing a burning and painful sensation throughout its existence within your oral cavity. It is not communicable in any way as it is an autoimmune condition. While its symptoms can be managed, proper monitoring is still necessary to ensure that the patient is not at risk of developing mouth cancer.

Celiac Disease

Celiac disease is an autoimmune condition that is often caused by a predisposing genetic factor – leading to damages in the small intestine every time a patient consumes gluten. A gluten-free diet and proper food management is the only way to manage the condition for now due to its aspect as an inherent condition that attacks the body from within.

Pemphigus Vulgaris

Pemphigus Vulgaris is another example of an autoimmune condition that causes blistering and erosion of the skin and mucus membranes, causing the formation of lesions and sores in middle-aged or older individuals. As the blisters rupture, it can often be painful, and its presence has likewise been found to cause losses in bodily fluids in protein, along with making eating and drinking very uncomfortable throughout.

Canker Sores

Canker sores are a type of mouth ulcerations caused by an underlying condition known as Aphthous Stomatitis, thus giving it the name “aphthous ulcers.” It is an autoimmune condition that suppresses the body’s defenses – encouraging it to produce blisters that are then ruptured to form painful sores. Unfortunately, the disease remains untreatable, but the symptoms can be managed to allow the patient to lead a more comfortable life.

Infectious Mononucleosis

Infectious Mononucleosis, commonly known as Mono or the “Kissing Disease,” is a contagious condition caused by the Epstein-Barr Virus – a pathogen known to be common among teenagers and young adults. Mono often presents extreme fatigue, fever, sore throat, body aches, and swollen lymph nodes. It is usually self-limiting – only requiring proper rest and fluid intake to aid the body as it fights through the infection.

Oral Thrush

Oral Thrush is a condition precipitated by having a yeast infection in your mouth – causing whiting to yellowish bumps to form on the inner cheeks and tongue of an infant and toddler. It is also known as oral candidiasis due to its causative microorganism, Candida albicans, thus, candidiasis.


Leukoplakia is a condition wherein a patient develops one or more whitish patches or lesions inside the mouth – eventually potentially developing into oral cancer, unlike in the case of oral thrush or lichen planus where it does not. It can be categorized into homogenous, where the patches are primarily white with smooth, wrinkled, or ridged surfaces that are consistent throughout, and non-homogenous, where the lesions can be white or white-red, and flat, nodular, or verrucous in shape and texture.

Sexually Transmitted Conditions that Cause Mouth Sores

To help you identify whether a sexually transmitted condition causes these manifestations, particularly in cases where you are sexually active, knowing the presentations of STDs that cause mouth sores will help ensure that abstinence, proper testing, and correct interventions are provided at the soonest possible time.



Chlamydia is a sexually transmitted condition caused by the microorganism known as Chlamydia trachomatis. It is a condition that has been shown to cause cervicitis in females and urethritis and proctitis in both sexes. It is commonly known as the “silent infection” due to its largely asymptomatic approach from a patient’s initial exposure until they develop more severe complications that could then be irreversible or may even be a cause for infertility in some.

For females, Chlamydial infections often target the cervix, causing symptoms such as mucopurulent discharge and an easily induced endocervical bleeding, along with other manifestations such as pyuria, dysuria, and urinary frequency. This could progress into what is known as Pelvic Inflammatory Disorder or PID, wherein affected individuals experience pelvic pain, cervical motion tenderness, and uterine tenderness.

On the other hand, infected males often present with mucoid or watery urethral discharge and dysuria, along with some instances of epididymitis where patients observe unilateral testicular pain, tenderness, and swelling.

Diagnostic Process

Several tests are available in various institutions that can be used to obtain a more conclusive diagnosis of the condition, but a nucleic acid amplification test or NAAT is often preferred due to its high sensitivity and accessible collection of specimens of examination (swab). However, your physician may likewise employ cell cultures to observe the viable presence of C. trachomatis, but this is often dependent on the availability and resources of other tests within the clinic.

Management or Treatment Regimen

Chlamydial infections are generally addressed with either a 7-day course of antibiotics or a single dose of antibiotics designed for single-administration regimens. However, note that abstinence is still recommended for all before, during, and seven days after the treatment course to ensure that no transmission occurs while the pathogen is still viable. Furthermore, immediate testing and prophylactic treatment may likewise be indicated for your partner, especially in cases of relatively recent sexual contact between the two.



Gonorrhea is a condition caused by a pathogen known as Neisseria gonorrhoeae – a microorganism that mainly targets the mucosal membranes of the body, causing manifestations and immediate infection following contact even despite the lack of any evident indications from an infected partner. With such a mechanism of transmission, it can likewise infect the cervix, uterus, fallopian tubes, and urethra.

Similar to how some STDs behave, Gonorrhea is a relatively asymptomatic condition at its initial stages, with certain exceptions, particularly for those who are symptomatic following the incubation period of the pathogen. For instance, gonorrheal infections in males often present as dysuria and a white, yellow, or green urethral discharge 1 to 14 days after exposure. In cases where complications such as epididymitis are evident, males may also experience testicular and scrotal pain along with the aforementioned symptoms.

In symptomatic females, gonorrheal infections are often mistaken for mild bladder and vaginal infections due to their presentation of dysuria, increased vaginal discharge, and vaginal bleeding between periods. However, it should be noted that while the symptoms are relatively minor, females are likewise at risk of developing severe complications.

Diagnostic Process

Gonorrheal infections are commonly diagnosed with a procedure known as a nucleic acid amplification test or NAAT – utilizing urine or urethral sample in men and an endocervical or vaginal sample in women to obtain a conclusive determination of the present microorganism within the genitalia. Furthermore, cell culture tests are likewise performed for such a condition, but utilization depends on the availability of NAATs as it remains the more specific and sensitive option among the rest.

Management or Treatment Regimen

The Centers for Disease Control and Prevention recommends a single administration of 500 mg IM Ceftriaxone to resolve most cases of gonorrhea, with certain exceptions depending on the tolerance of the patient and the overall availability of the drug in the market. Note that a test-of-cure is likewise required for patients undergoing Gonorrheal treatment to ascertain that the pathogen is responding to the medication and that the condition is being cured instead of being simply asymptomatic.



Notorious for the severity and extent of its complications, Syphilis is a sexually transmitted condition caused by the pathogen known as Treponema pallidum that mimics various other conditions – giving it the infamous name of “the great pretender.” The disease itself progresses consistently for months or years without proper intervention, and its progression is divided into four stages: the primary stage, the secondary stage, the latent stage, and the tertiary stage.

In the primary stage, the first chancres are observed – presenting as a round, firm, and painless lesion usually found at the point of exposure and is usually resolved without any intervention. However, the condition progresses into its secondary stage without proper management, wherein rashes and mucus membrane lesions, particularly in the mouth, vagina, and anus, are observed. Chancres may likewise appear in this stage along with rough, red, or reddish-brown spots/rashes both on the palms of the hand and bottoms of your feet. Condyloma lata or large, raised, gray or white lesions may also be observed in the warm and moist areas of the body, along with other symptoms such as fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle ache, and fatigue. Without any treatment at this stage, it will continue to progress into its latent phase, wherein the condition does not present any signs or symptoms at all. If no proper intervention is still provided at this point, it could then reach its most severe stage or the tertiary stage – the point where it now affects multiple organs such as the brain, nerves, eyes, heart, blood vessels, liver, and joints.

Diagnostic Process

In diagnosing potentially syphilitic cases, physicians commonly use treponemal tests as these are designed to detect antibodies specific to T. pallidum, allowing physicians to see the presence of the pathogen as early as possible and will enable them to detect the presence of treponemal antibodies from previous infections. With this in mind, physicians commonly request a non-treponemal test with titer as a confirmatory procedure to rule out previous infections, particularly in cases where the patient has a history of the disease.

Management or Treatment Regimen

The following treatment regimens are recommended by the Centers for Disease Control and Prevention depending on the stage the patient’s syphilis infection is at:

  • Adults and adolescents with primary, secondary, or early latent syphilis: Benzathine Penicillin G 2.4 million units IM single dose
  • Adults and adolescents with late latent or latent syphilis of unknown duration: Benzathine Penicillin G 7.2 million units in total, administered in 3 doses of 2.4 million units each IM every week
  • Neurosyphilis, ocular syphilis, otosyphilis: Aqueous Crystalline Penicillin G 18-24 million units/day, administered as 3-4 million units IV every 4 hours or continuous infusion for 10-14 days.

Oral Herpes


Herpes, in general, is a condition that can be found in various parts of the body due to the two variations of its causative microorganism: herpes simplex virus type 1 and type 2 (HSV-1, HSV-2). The two variations are sometimes incorrectly interchanged because people commonly assume that the manifestation of both is similar in all aspects. Both the HSV-1 and HSV-2 strains are shed even from normal-appearing genitalia – making it harder to discern whether an individual is infected or not. However, one should note that HSV-1 is the most common causative agent for oral infections, while both HSV-1 and HSV-2 can cause genital manifestations.

Oral herpes (HSV-1) can be spread from mouth to genitalia through oral sex. It commonly results in the presence of cold sores and blisters on or around the mouth, and it is transmitted through either a herpes sore, the saliva from an infected person, or contact with either the mouth or genitalia of an infected individual.

Diagnostic Process

Similar to how other conditions are diagnosed, nucleic acid amplification tests remain the gold standard for diagnosis due to their high sensitivity to the presence of any markers for the infection. However, it should likewise be noted that cell cultures and type-specific virologic tests may likewise be utilized, especially in cases where the resources are scarce, or if the patient has recurrent symptoms and are constantly shifting through periods of high and low viral shedding to provide an accurate NAAT result, respectively.

Management or Treatment Regimen

As of this writing, there is no cure or treatment for herpes as it is considered a lifetime infection. However, one should note that the condition can still be managed and confined to undetectable levels – allowing previously infected individuals to still resume their daily life amidst having the infection. Daily suppressive therapy is often provided to ensure that the condition never progresses into a more severe disease that could cause irreversible damage.

Human Papillomavirus (HPV)


HPV or Human Papillomavirus is one of the most common sexually transmitted diseases globally due to how it can be easily transmitted despite the lack of evident symptoms or manifestations. It is caused by the pathogen of the same name, HPV, and it usually goes away on its own without any significant presentations for as long as it does not progress into a more aggressive condition that presents with specific clinical manifestations. In cases where the disease is symptomatic, the commonly observed symptomatic evidence for HPV is the presence of warts that appear as a small bump or group of bumps within the genital area. The warts may vary in nature, with some large, some raised or flat, and some that might even look like a cauliflower. However, note that the growths are not only restricted within the genitalia and may likewise be observed in the scrotum, anus, mouth, and throat, depending on the areas exposed to the infected surface.

Diagnostic Process

It is currently challenging to diagnose HPV infections due to its mainly asymptomatic nature and the absence of a standard test that can be used for the presence of HPV in the mouth and throat. As of this writing, the most common HPV test used to identify genital warts is a test used to screen for cervical cancer. This test, however, is only recommended for women aged 30 years or older.

Management or Treatment Regimen

There is currently no known treatment regimen for the presence of the virus itself as the condition is generally self-limiting. However, your physician may provide a prescription medication for removing your warts as leaving a visible wart with no intervention will risk its growth, albeit it might also stay the same or disappear altogether.

Frequently Asked Questions (FAQs)

Is mono considered a sexually transmitted infection?

Technically, in cases where it is transmitted sexually, but not in those where the virus was obtained through kissing.

Can syphilis cause alopecia?

Yes. It can cause patchy or diffuse non-scarring hair loss during its late stages.

Can late-stage syphilis still be managed?

Yes. However, any structural damage that it might have caused is already irreversible.

How long can HPV persist in the body without any significant intervention?

Most cases would usually report that HPV persists for 1 to 2 years as the immune system attempts to fight off the infection.

Is it possible to be reinfected with HPV upon contracting it once?

Yes. Reinfection is possible upon coming into contact with the causative organism again.


American Journal of Public Health

World Health Organization

Nemours Teens Health

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Written by Mark Riegel, MD

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