Vulvar sores take many forms, from tiny fluid-filled blisters that cluster together to deep, clean-edged ulcers that sit alone, to raw red patches that look more like irritated skin than a distinct wound. Their appearance depends almost entirely on what is causing them, and the list of possible causes runs far longer than most people expect. Sexually transmitted infections account for many cases, but autoimmune conditions, inflammatory diseases, medications, and even cancers can all produce sores on the vulva that look surprisingly similar to one another at first glance.
Herpes Simplex Virus
Genital herpes is the most common infectious cause of vulvar ulcers in many parts of the world, and it tends to look different the first time it appears compared with later outbreaks. A primary (first-ever) episode usually produces multiple small blisters that quickly break open into shallow, painful ulcers. These lesions appear on both sides of the vulva, and the surrounding skin is often red and swollen. Pain and itching are reported in almost all first episodes, and more than half of people also experience painful urination, tender swollen lymph nodes in the groin, and flu-like symptoms such as fever and body aches. The sores from a first outbreak last roughly three weeks on average before healing on their own.1PubMed. Genital herpes simplex virus infections: clinical manifestations, course, and complications
Recurrent outbreaks paint a different picture. The blisters tend to be fewer in number, smaller, and clustered on one side of the vulva rather than both. Systemic symptoms like fever are uncommon, and about a quarter of recurrent episodes produce no noticeable symptoms at all. Healing time drops to about ten days. Virus shedding also falls off sharply compared with the initial infection, which partly explains why recurrences are often milder and shorter.2PubMed Central. Clinical and virologic course of herpes simplex genitalis
The classic progression is blister → ulcer → crust → healed skin. In practice, though, many people never notice the blister stage and only see a raw, shallow sore. On moist vulvar tissue the crusting stage sometimes does not happen at all, so the ulcer simply fills in from below. If you are looking at a cluster of small, round, shallow ulcers with a red base and grayish center, herpes is high on the list of possibilities.
Syphilis
The hallmark of primary syphilis is the chancre, a single, round, painless ulcer with a clean, raised border and a smooth base. It shows up wherever the bacterium entered the body, which on the vulva can be the labia, clitoris, or vaginal opening. Because it is painless, a chancre often goes unnoticed entirely, especially if it forms inside the vagina or on the cervix. It usually appears about three weeks after exposure and heals on its own within a few weeks, even without treatment, which creates a false sense of reassurance.
The “classic” chancre is taught in textbooks, but real-world syphilis can look far less tidy. Atypical chancres vary widely in size, shape, and number. They can be tiny, giant, or deep enough to cause scarring. In skin folds of the vulva they may appear as linear cracks rather than round ulcers, and multiple chancres can cluster together in a pattern that mimics herpes.3PubMed. Syphilis: uncommon presentations in adults If secondary syphilis develops weeks later, it produces flat, moist, wart-like patches called condylomata lata on the vulva, along with a rash elsewhere on the body. These lesions are teeming with bacteria and highly contagious.
Chancroid and Other Tropical Sexually Transmitted Infections
Chancroid produces one or more deep, ragged, painful ulcers with undermined (overhanging) edges and a dirty-looking gray or yellow base. The ulcers bleed easily when touched. More than half of people with chancroid also develop large, tender, swollen lymph nodes in the groin that can break down into pus-filled abscesses called buboes.4PubMed. Chancroid: clinical manifestations, diagnosis, and management The combination of a painful, soft ulcer plus bubo is considered classic for chancroid, whereas syphilis produces a painless, firm ulcer. In practice, though, the two conditions can overlap in appearance, and co-infection is possible.
Two other sexually transmitted infections, donovanosis (granuloma inguinale) and lymphogranuloma venereum (LGV), are rare in high-income countries but worth knowing about for travelers or anyone in endemic regions. Donovanosis causes beefy-red, slowly expanding, painless ulcers that bleed on contact and, left untreated, progressively destroy tissue over months. LGV starts as a small, often unnoticed sore at the site of contact and then moves into lymph nodes, producing dramatic groin swelling and systemic illness.5Dermatologic Clinics. Chancroid, Donovanosis, and Lymphogranuloma Venereum
Lipschütz Ulcers
Not every vulvar ulcer in a young person signals a sexually transmitted infection. Lipschütz ulcers (also called acute vulvar ulcers or ulcus vulvae acutum) typically appear in adolescents and young women who have never been sexually active, which understandably causes alarm and sometimes leads to a misdiagnosis of an STI or, worse, suspicion of sexual abuse.6Ewha Medical Journal. Acute Vulvar Ulcer (Lipschutz Ulcer) in a Sexually Inactive 11-Yearold Girl
The ulcers come on suddenly, often after a viral illness or flu-like symptoms, and present as one or several deep, painful ulcers on the inner labia or vaginal opening. They can be covered with a gray or necrotic membrane and look alarming in size. Despite appearances, Lipschütz ulcers are self-limiting: most resolve within about two weeks without specific treatment and do not recur.7PubMed Central. Acute genital ulcers Diagnosis is largely clinical, made after ruling out infections through testing. Treatment focuses on pain relief. The condition is thought to be linked to an immune reaction, possibly triggered by Epstein-Barr virus or other common infections, rather than by direct infection of the vulvar tissue itself.8PubMed Central. Ulcer of Lipschutz, a rare and unknown cause of genital ulceration
Behçet’s Disease
Behçet’s disease is an inflammatory condition that causes recurring ulcers in the mouth and on the genitals, along with possible eye inflammation, skin lesions, and joint pain. The genital ulcers look a lot like the mouth ulcers that characterize the disease: round or oval, with a sharp border, a yellow-gray base, and a surrounding red halo. They are painful and can be deep enough to leave scars after healing, which helps distinguish them from herpes or aphthous ulcers that tend to heal without scarring.9JEADV Clinical Practice. The skin in Behçet’s disease: Mucocutaneous findings and differential diagnosis
Because Behçet’s is a systemic condition, vulvar ulcers rarely appear in isolation. If you are dealing with recurring mouth sores alongside genital ulcers, that pattern is a strong clue. The ulcers tend to flare and remit over months or years, and stopping prescribed anti-inflammatory medications can trigger new sores. In one reported case, a patient who self-discontinued corticosteroids due to weight gain developed a recurrent vulvar ulcer within months, which then responded to topical steroids and colchicine.10PubMed Central. Case Report: Giant vulvar ulcer caused by Behcet’s disease
Lichen Sclerosus and Lichen Planus
These are chronic inflammatory skin conditions that commonly affect the vulva but are not infections and are not contagious. They can produce sore, raw areas that patients describe as “sores” even though the underlying process is different from an ulcer caused by a virus or bacterium.
Lichen sclerosus classically produces thin, white, crinkled skin on the vulva, sometimes described as looking like cigarette paper. In more advanced or untreated cases, the skin can crack, fissure, and erode. Erosive lichen sclerosus typically shows up as red patches on hairless vulvar skin, with a gentle slope from normal tissue into the raw area. Ulcerated lichen sclerosus, by contrast, presents as deeper breaks in the skin, often on hair-bearing areas, sometimes on a background of thickened white plaques. In one study, over half of ulcerated cases were described as lichenified skin with visible breaks through the surface. Ulcerated disease was linked to untreated lichen sclerosus and to diabetes.11PubMed Central. Erosive Lichen Sclerosus—A Clinicopathologic Subtype
Erosive lichen planus produces bright red, raw, glazed-looking patches on the vulva, often at the vaginal opening and inner labia. The borders of the erosion may show a delicate white, lacy pattern called Wickham’s striae, which is a helpful diagnostic clue when visible. Some people develop both lichen planus and lichen sclerosus at the same time, a combination that can show central redness surrounded by peripheral white pallor.12PubMed Central. Treatment strategies for erosive genital lichen planus: A systematic review of therapeutic modalities and emerging breakthroughs Both conditions are associated with autoimmune disease: roughly a quarter to a third of patients with either condition have a coexisting autoimmune disorder, and circulating autoantibodies are found at higher rates than in the general population.13JAMA Dermatology. The Association of Lichen Sclerosus and Erosive Lichen Planus of the Vulva With Autoimmune Disease: A Case-Control Study
Crohn’s Disease of the Vulva
Crohn’s disease is best known as a bowel condition, but it can produce skin manifestations well away from the gastrointestinal tract. On the vulva, Crohn’s may cause deep, knife-cut ulcers along the skin folds, sometimes with surrounding swelling that makes the labia appear thickened and edematous. One reported case involved a young woman with vulvar swelling and multiple oval, linear, knife-cut deep ulcers on the perineal folds, with biopsy showing the granulomas characteristic of Crohn’s.14PubMed Central. Refractory cutaneous Crohn’s disease of the external genitalia in a female
Vulvar Crohn’s can appear before, during, or after bowel symptoms develop, and in some cases the vulvar disease shows up with no gastrointestinal complaints at all, which makes diagnosis tricky. The ulcers can be chronic, painful, and resistant to standard wound care. Treatment usually requires systemic medications targeting the underlying inflammatory process, not just local wound management.
Fixed Drug Eruptions
A cause of vulvar sores that catches many people off guard is the fixed drug eruption: a reaction to a medication that produces a sore at the same spot on the body every time the drug is taken. On the vulva, this can present as a round, dusky-red or purple patch that evolves into a blister or erosion. The key feature is that the sore reappears in exactly the same location with each exposure to the offending medication and clears up when the drug is stopped.
Sulfonamide antibiotics are among the most common triggers, but the list also includes NSAIDs like ibuprofen, tetracycline antibiotics, anticonvulsants, and cholesterol-lowering statins.15PubMed Central. Vulvar fixed drug eruption: a rare manifestation of cutaneous adverse drug reaction In a case series of 13 women, two younger patients had acute recurring vulvitis tied to ibuprofen use, while seven older women (ages 58 to 77) had chronic erosive vulvitis that failed to respond to every treatment tried until the responsible drug, often a statin or COX-2 inhibitor, was finally identified and stopped.16PubMed. Vulvar fixed drug eruption. A report of 13 cases An earlier study found that when the genital area was the only site affected, patients tended to seek help sooner, but drug history was still the main way to reach the diagnosis.17PubMed. Genital fixed drug eruptions
If you have a vulvar sore that keeps coming back and you happen to take a medication intermittently, it is worth raising the possibility of a fixed drug eruption with your doctor. The resolution after stopping the drug is usually rapid and dramatic.
When a Sore Could Be Cancer
Most vulvar sores are not cancer, but vulvar cancer can present as a sore, and ignoring a persistent ulcer has real consequences. Vulvar cancer often shows up as itching, pain, a visible lump, or an ulcer that does not heal. The most common subtype is squamous cell carcinoma.18PubMed Central. Cancer of the vulva: 2021 update
The concern intensifies when a sore has been present for weeks or months without healing, especially in postmenopausal women. In one study of 80 women with squamous cell disease of the vulva, about one in seven initially presented with a persistent vulvar ulcer. The median age was 72. Alarmingly, over half of those who had an office biopsy before referral received a benign result on that first biopsy, only for invasive cancer to be found on the subsequent excision.19Menopause. The risk of squamous cell carcinoma in persistent vulvar ulcers That finding underscores why any vulvar ulcer that does not resolve within a reasonable timeframe deserves a biopsy, and why a single benign biopsy result does not always close the book on the question.
How Clinicians Tell These Causes Apart
Appearance alone is not enough to diagnose most vulvar sores, because many of the conditions above can mimic each other. A clinician evaluating a vulvar ulcer will typically combine a careful history (sexual activity, medications, timeline, systemic symptoms) with physical examination and targeted testing. Common diagnostic tools include swab-based tests for herpes (PCR or viral culture), blood tests for syphilis, and biopsy for inflammatory or potentially cancerous lesions.20PubMed Central. Genital Ulcer: A Diagnostic Challenge
A few patterns can help narrow the field before test results return:
- Painful clusters of small blisters or shallow ulcers: herpes is the leading possibility, especially if there have been prior episodes.
- Single, painless, firm ulcer: classic for syphilis, though atypical presentations are common.
- Deep, ragged, painful ulcer with bubo: points toward chancroid.
- Sudden deep ulcers in a young, non-sexually active person after a viral illness: consider Lipschütz ulcer.
- Recurring mouth and genital ulcers together: Behçet’s disease is high on the list.
- White, crinkly, or thickened skin with fissures or raw patches: lichen sclerosus or lichen planus.
- Sore that reappears in the same spot after taking a medication: fixed drug eruption.
- Non-healing ulcer in an older adult: biopsy to rule out cancer.
Vulvar Sores During Pregnancy
Pregnancy adds urgency to vulvar sore evaluation because certain infections, particularly herpes simplex and varicella zoster, can affect the pregnancy and the newborn. Herpes simplex poses the greatest risk when a primary outbreak occurs near the time of delivery, because neonatal herpes, though uncommon, carries serious consequences. Varicella zoster (the same virus that causes chickenpox and shingles) can also appear on the vulva and requires prompt treatment in pregnancy.21PubMed Central. Genital VZV in a Third Trimester Pregnancy and the Critical Role of Interdisciplinary Planning If you are pregnant and notice any new vulvar sore, getting it evaluated quickly rather than waiting matters for both your health and the baby’s.
Folliculitis, Abscesses, and Other Bumps That Are Not Ulcers
Not every painful lump on the vulva is a sore or ulcer. Folliculitis (inflamed hair follicles) produces small red bumps, often with a white or yellow head, that can be mistaken for herpes at a glance. They tend to appear in hair-bearing areas after shaving, waxing, or friction from tight clothing. Unlike herpes blisters, folliculitis bumps are centered around a hair shaft.
Bartholin gland cysts form near the vaginal opening and can become abscesses if infected, producing a painful, swollen lump. Hidradenitis suppurativa causes recurring, painful nodules and abscesses in the groin and vulvar area that can drain and form sinus tracts over time. These conditions are not true ulcers in the medical sense, but they produce painful lumps and sometimes open wounds that patients understandably describe as sores. A clinician can usually distinguish them on exam based on their location, depth, and whether they recur in a predictable pattern.
When to Get Evaluated
Any new vulvar sore that you cannot confidently explain (for example, a known shaving nick) is worth having looked at, but certain features raise the urgency. A sore accompanied by fever, widespread rash, joint pain, or headache suggests a systemic process that may need rapid evaluation. One case report described a previously healthy 30-year-old woman who developed rapidly worsening labial pain and swelling, followed within days by fever, a pustular rash across her chest and arms, and joint pain, illustrating how quickly a vulvar complaint can signal something broader.22PubMed Central. Labial pain and swelling with fever
Other signs that warrant prompt attention include a sore that has persisted for more than two to three weeks, an ulcer that is growing rather than shrinking, significant pain that interferes with sitting or urinating, or any sore that appeared in the context of a new sexual partner. If you have already been treated for a vulvar condition and a sore keeps coming back despite therapy, returning for re-evaluation, and possibly a biopsy, is the right move. The overlap in appearance between benign and serious conditions means self-diagnosis based on what a sore looks like carries real risk.