Most vaginal and vulvar sores are caused by infections, and the majority respond well to treatment once correctly diagnosed. Genital herpes is the single most common culprit, but sores can also stem from syphilis, inflammatory skin conditions, autoimmune diseases, reactions to medications, and even causes that have nothing to do with sexual activity. Because these causes look surprisingly similar on the surface, getting the right diagnosis is the essential first step before any treatment can help.
Why “Vaginal Sores” Can Mean So Many Different Things
The term “vaginal sores” gets used loosely to describe ulcers, blisters, erosions, or raw patches anywhere on the vulva, labia, vaginal opening, or inside the vaginal canal. Clinically, these lesions differ quite a bit. A herpes outbreak typically starts as small fluid-filled blisters that rupture into shallow, painful ulcers. Syphilis produces a single firm, painless sore called a chancre. Inflammatory conditions can cause slow-spreading erosions that look nothing like either one. A sore’s location, whether it hurts, how many there are, and how long it has been present all help narrow the diagnosis, but even experienced clinicians sometimes need lab confirmation to tell one from another.
Genital Herpes, the Most Common Cause
Herpes simplex virus (HSV) is behind most cases of recurring genital sores. A first outbreak tends to be the worst, sometimes producing clusters of painful blisters along with flu-like symptoms and swollen lymph nodes. After that initial episode, the virus stays dormant in nerve cells and can reactivate periodically, though recurrences are usually shorter and milder. The lesions go through a recognizable sequence of blisters, open ulcers, crusting, and healing, but that progression can look different depending on the person’s age and immune status, which sometimes creates diagnostic confusion.
Herpes is diagnosed most reliably by testing fluid from an active sore. PCR testing has a substantially higher detection rate than older viral culture methods and is now considered the preferred approach for people with active lesions, regardless of the sore’s location or which HSV type is involved. Blood tests that look for type-specific antibodies can identify people who carry the virus without symptoms, but widespread screening with these tests is not generally recommended.
Treatment uses antiviral drugs. Valacyclovir and acyclovir are the mainstays, and clinical trials involving thousands of patients have found them equally effective at shortening outbreaks. In head-to-head comparisons, both drugs cut the duration of a recurrent episode by roughly a day compared to placebo, reduced pain duration, and stopped viral shedding faster. About a quarter of patients treated early enough had “aborted” episodes where lesions never progressed beyond a small bump. Valacyclovir has the practical advantage of simpler dosing: it is the only antiviral approved for once-daily suppressive therapy and also for a short three-day course to treat recurrent episodes. A trial comparing three-day and five-day courses of valacyclovir found no meaningful difference in healing time, pain duration, or episode length, so the shorter regimen works just as well for most people.
Syphilis and Other Bacterial Causes
Syphilis is the other major sexually transmitted cause of genital sores, and it deserves special attention because it is both curable and dangerous if ignored. The primary stage produces a chancre, a round, firm sore that is usually painless and appears at the site of infection. Because it does not hurt, it is easy to overlook or dismiss, which is exactly what makes syphilis tricky. Left untreated, the infection progresses through stages that can eventually damage the heart, brain, and other organs.
The standard treatment for primary syphilis is a single injection of benzathine penicillin. For people allergic to penicillin, doxycycline taken orally over two weeks is an alternative; research comparing the two has found similarly high rates of serological cure. The key with syphilis is catching it early, which brings us back to the importance of getting any unexplained genital sore checked out rather than assuming it is something benign.
Less common bacterial infections that can cause genital ulcers include chancroid and lymphogranuloma venereum (LGV). Chancroid produces soft, painful sores and is treated with a single dose of azithromycin or a short course of other antibiotics. LGV, caused by specific strains of chlamydia, starts as a small painless bump that often goes unnoticed before progressing to painful swollen lymph nodes. Both are relatively rare in high-income countries but worth knowing about if you have traveled to areas where they are more common.
When Sores Have Nothing to Do With Sex
Not every genital ulcer is sexually transmitted, and this is a point that matters enormously for the people affected, many of whom are teenagers and young women who have never been sexually active. Lipschütz ulcers are a prime example. These are sudden-onset, painful vulvar ulcers that can look alarming, with deep, necrotic-appearing bases and irregular borders. They typically appear as bilateral “kissing” ulcers on the inner surfaces of the labia. The condition predominantly affects adolescents and young women and is frequently underrecognized. Acute genital ulcers of this type have been linked to infections like Epstein-Barr virus and, more recently, to other viral triggers including SARS-CoV-2, though in many cases no clear cause is found.
Lipschütz ulcers are self-limiting, meaning they heal on their own within a few weeks. Treatment focuses on pain control and wound care rather than antibiotics or antivirals. The real challenge is the diagnostic process: because the sores can look so much like herpes or syphilis, patients and families sometimes endure unnecessary distress and suspicion before the correct diagnosis is reached. Awareness of this condition among clinicians has improved, but it remains underrecognized.
Inflammatory Skin Conditions That Cause Vulvar Sores
Two chronic skin conditions deserve mention because they commonly affect the vulva and can produce persistent sores or erosions that are often misidentified as infections.
Lichen sclerosus causes thinning, whitening, and fragility of vulvar skin. In some cases it progresses to an erosive form, where the skin breaks down into raw, painful areas that can be mistaken for herpes or other infections. The gold standard treatment is a high-potency topical corticosteroid, typically clobetasol propionate applied to the affected area twice daily for about twelve weeks. This regimen significantly reduces symptoms and improves the skin’s appearance in most patients. After the initial intensive phase, maintenance therapy at a lower frequency helps keep flares under control. If standard topical treatment fails, topical calcineurin inhibitors are considered a second-line option. European guidelines also recommend using emollients alongside steroids to support the skin barrier.
Lichen planus, particularly its erosive form, is more challenging to manage. Erosive vulvovaginal lichen planus produces bright red, painful erosions that can affect the vulva, vagina, and even the mouth simultaneously. Topical corticosteroids are tried first, but the response rate is lower than with lichen sclerosus. Some patients require systemic medications, though the evidence base for these is limited. A key reason to get an accurate diagnosis is that both lichen sclerosus and lichen planus, if left untreated for years, carry a small but real increased risk of vulvar cancer.
Behçet’s Disease and Other Systemic Causes
Behçet’s disease is a chronic inflammatory condition that causes recurring painful ulcers in the mouth and genitals, along with other symptoms like skin lesions and eye inflammation. The genital ulcers can be deep, slow to heal, and intensely painful. Behçet’s is rare, but it is worth considering when someone has recurring genital sores alongside oral ulcers that do not fit an infectious pattern. The condition goes through flares and remissions of varying intensity, and treatment typically involves corticosteroids, colchicine, or immunosuppressive drugs depending on the severity. Steroid pulse therapy has been used for severe genital ulcerations in Behçet’s disease.
Crohn’s disease, an inflammatory bowel condition, occasionally produces genital ulcers as well, sometimes even before gut symptoms appear. These so-called “metastatic” Crohn’s lesions are treated by managing the underlying disease rather than treating the ulcers locally.
Medications That Can Cause Genital Ulcers
Fixed drug eruptions are an underappreciated cause of genital sores. In this reaction, a medication triggers a localized inflammatory response that reappears in the exact same spot every time the drug is taken. The genital area is one of the most common sites for fixed drug eruptions. The sores start as a round, red or dusky patch and can blister or ulcerate. Non-steroidal anti-inflammatory drugs, certain antibiotics (including tetracyclines), and sulfonamides are among the most frequently implicated medications. The treatment is straightforward once the connection is identified: stop the offending drug and the sore heals. The challenge is recognizing the pattern, since the link between a medication and a genital sore is not always obvious to the patient or their doctor.
When a Sore Could Be Cancer
Vulvar cancer is uncommon, but it can present as a non-healing ulcer, a lump, or a persistent sore, sometimes alongside itching, burning, or bleeding. In a study of women with vulvar squamous cell disease, roughly one in seven presented with a persistent vulvar ulcer as their primary complaint. Most of these women were postmenopausal, with a median age in the early seventies. A sobering finding from that study was that over half of the women who had an initial office biopsy received benign results, only to be diagnosed with invasive cancer after a more thorough excision. That means a single biopsy showing “nothing worrisome” does not always rule out cancer if the sore persists.
This finding underscores a practical rule: any vulvar sore that has not healed within a few weeks, especially in an older adult, warrants a biopsy. If the biopsy comes back benign but the sore still has not healed after treatment, pushing for re-evaluation is reasonable. Vulvar cancer caught early has a very good prognosis; the danger lies in delayed diagnosis.
When to See a Doctor
The short version is that any new, unexplained sore on the vulva or vaginal area deserves a medical evaluation, even if you think you know what it is. Self-diagnosis is unreliable with genital sores because different conditions mimic one another closely. That said, some situations are more urgent than others:
- First occurrence: If you have never had a genital sore before, get it checked. A first herpes outbreak needs antiviral treatment, and a syphilis chancre needs antibiotics before it disappears on its own and the infection silently progresses.
- Severe pain or fever: A first herpes episode can occasionally be severe enough to cause urinary retention or significant systemic illness. If you are running a fever alongside genital sores, do not wait it out.
- Sores lasting more than two to three weeks: Self-limiting causes like Lipschütz ulcers or mild herpes recurrences typically begin healing within that window. Anything that lingers needs investigation, particularly to rule out inflammatory conditions or cancer.
- Pregnancy: Herpes and varicella zoster virus can both affect the baby through vertical transmission or neonatal infection. Accurate diagnosis and prompt treatment during pregnancy is critical, and decisions about delivery method may depend on whether active lesions are present at the time of labor.
- Recurring sores without a diagnosis: If you keep getting genital ulcers and have never had a clear diagnosis, conditions like Behçet’s disease, lichen planus, or fixed drug eruptions should be considered.
Home Care and Comfort Measures
While you are waiting for a diagnosis or during treatment, a few simple steps can make genital sores more bearable. Keeping the area clean and dry helps prevent secondary bacterial infection. Warm sitz baths can soothe pain. Wearing loose cotton underwear reduces friction. Over-the-counter pain relievers like ibuprofen or acetaminophen take the edge off. For herpes sores specifically, applying a cool compress and urinating in a warm bath can ease the stinging. Avoid applying over-the-counter antibiotic ointments or harsh antiseptics unless directed by a clinician, since some products can irritate already-damaged tissue.
If you have been prescribed topical corticosteroids for a condition like lichen sclerosus, apply them exactly as directed. It can be tempting to stop using them once symptoms improve, but undertreating these conditions leads to flares and progressive skin changes.
Partner Notification and Preventing Reinfection
For sexually transmitted causes, treating only yourself without addressing your partner is a recipe for reinfection. With bacterial infections like chlamydia and syphilis, your partner needs testing and treatment. Research on patient-delivered partner treatment, where the patient carries medication to their partner, has shown some promise in reducing reinfection rates, though the approach works best when combined with encouraging partners to get their own evaluation.
For herpes, the conversation is different because the virus cannot be cured, only managed. Daily suppressive antiviral therapy reduces both the frequency of outbreaks and the risk of transmitting the virus to a partner. Consistent condom use further lowers transmission risk but does not eliminate it, since herpes can shed from skin not covered by a condom. Being upfront with partners about your status, while emotionally difficult, is both an ethical obligation and a practical one.
The Emotional Weight of Genital Sores
The physical discomfort of genital sores is only part of the picture. A diagnosis of genital herpes, in particular, carries a stigma that is out of proportion to its actual medical severity. Research consistently shows that people with recurrent genital herpes experience higher rates of depression and anxiety compared to the general population. One prospective study found that roughly three in ten participants with recurrent HSV-2 had baseline depression, compared to fewer than one in ten controls. Stigma and sexual distress scores remained elevated over a full year of follow-up.
The psychological burden is not just a side effect; it can feed the physical problem. Stress and negative emotions are associated with more frequent herpes recurrences, and frequent recurrences reinforce the sense of stigma, creating a self-perpetuating cycle. Addressing the emotional side of the diagnosis, whether through counseling, support groups, or simply having an honest conversation with a knowledgeable healthcare provider, matters for both mental health and outbreak management. If a diagnosis of genital sores has left you feeling isolated or anxious, that is a normal response, and it is also something that can be helped.
Fixed Drug Eruptions and Diagnostic Traps
One of the more frustrating scenarios is being treated for an infection you do not actually have. This happens more often than you might expect with genital sores. A woman presents with a painful vulvar ulcer, gets tested for herpes and syphilis, and when those come back negative, the sore is sometimes dismissed or treated empirically with antibiotics “just in case.” Meanwhile, the actual cause, whether it is a fixed drug eruption, lichen planus, Lipschütz ulcer, or Behçet’s disease, goes unaddressed.
If your STI tests are negative and your sore is not healing as expected, ask your clinician to consider non-infectious causes. A dermatologist or vulvar specialist may be more experienced with the less common diagnoses. Biopsy is sometimes the only way to distinguish between inflammatory conditions, and it is a straightforward office procedure. The goal is not just to treat the sore in front of you but to figure out why it appeared, so you can prevent or manage future episodes effectively.
Vulvar Care After Menopause
Postmenopausal women face a specific set of vulnerabilities when it comes to vulvar sores. Declining estrogen levels lead to thinner, drier, less elastic vulvar and vaginal tissue, a condition called vulvovaginal atrophy. This fragile tissue tears and ulcerates more easily from minor friction or irritation, and those small breaks can be mistaken for infections. Topical estrogen therapy can restore tissue thickness and resilience, which in turn reduces the frequency of these superficial injuries.
More importantly, as noted in the cancer section above, persistent vulvar ulcers in postmenopausal women have a meaningful chance of harboring squamous cell carcinoma, and initial biopsies can miss it. Women in this age group should take any non-healing vulvar sore seriously and insist on thorough evaluation. The median age of the cancer patients in the study cited earlier was 72, a reminder that vulvar health deserves attention well beyond the reproductive years.