Most nasal sores are caused by a bacterial infection, a cold-sore outbreak, or simple mechanical damage from dry air and nose picking. Staphylococcus aureus, the same bacterium behind many skin infections, is the single most frequent culprit, colonizing the front of the nasal passages where it can infect any small break in the lining. While the vast majority of nasal sores heal on their own or with basic treatment, some signal rarer conditions that deserve medical attention, and a few red flags warrant a prompt visit to a doctor.
Bacterial Infections Are the Leading Cause
The nasal vestibule, the area just inside each nostril where skin meets moist mucous membrane, is the most common site for nasal sores. An infection here is called nasal vestibulitis, and it typically shows up as a tender, red, sometimes pus-filled bump. A retrospective review of 118 cases found that among patients whose sores were cultured, methicillin-sensitive Staphylococcus aureus was the most common isolate, appearing in roughly four out of five positive cultures.1PubMed. Nasal vestibulitis: etiology, risk factors, and clinical characteristics: A retrospective study of 118 cases That makes sense when you consider that Staph aureus permanently lives in the noses of about a quarter to a third of healthy people. Normally it causes no trouble, but any crack in the lining, from a cold, blowing your nose hard, or trimming nasal hair too aggressively, gives the bacteria an opening.
A minor vestibulitis might look like a single painful pimple inside your nostril. More advanced infections can form a boil (furuncle) that swells, throbs, and sometimes drains on its own. The concern with nasal boils is their location: the veins draining this area connect to deeper structures in the skull. In rare cases, an untreated or squeezed nasal boil can lead to cavernous sinus thrombosis, a dangerous blood clot inside the skull. Case reports have documented this complication arising from nasal infections, even in children.2PubMed Central. Cavernous sinus thrombosis of nasal origin in children The practical takeaway: do not squeeze a boil inside your nose the way you might pop a pimple elsewhere on your face.
Cold Sores Inside the Nose
Herpes simplex virus type 1, the same virus behind cold sores on the lips, can produce painful blistering sores on or inside the nose. Initial infection often arrives with systemic symptoms such as fever, headache, and muscle aches, followed by a progression from small raised spots to fluid-filled blisters that burst, ulcerate, and crust over within a few days.3PubMed Central. Nasal Herpes Simplex With Infraorbital Neuralgia: A Rare Presentation After the first episode, the virus retreats into sensory nerve cells and stays dormant there indefinitely.
Recurrent outbreaks tend to be milder than the initial one. They can show up as subtle sores inside the nose or on the nasal septum that heal and return, sometimes in the same spot each time.4Journal of Antimicrobial Chemotherapy. The many challenges of facial herpes simplex virus infection Triggers for reactivation include stress, sun exposure, menstruation, fever, cold weather, and anything that temporarily weakens the immune system.3PubMed Central. Nasal Herpes Simplex With Infraorbital Neuralgia: A Rare Presentation If you get recurrent blistering sores in the same area of your nose, herpes simplex is a strong possibility. A doctor can confirm the diagnosis with a swab and prescribe antiviral medication that shortens outbreaks.
Nose Picking, Dry Air, and Everyday Trauma
This is probably the most common cause of nasal sores that people never bring up with a doctor. Picking or rubbing the inside of the nose damages the delicate mucosal lining, creating small tears that sting, scab over, and invite bacterial infection. A published case report illustrated how nose picking in a hot, dry climate led to mucosal excoriation that allowed Staphylococcus to enter the bloodstream and seed an infection in the spine.5BMJ Case Reports CP. The perils of picking your nose: paraspinal staphylococcal infection in a traveller returning from a dry and dusty land That is an extreme outcome, but it underscores the principle: breaking the nasal lining opens the door to bacteria that are already living right there.
Dry air, whether from winter heating, air conditioning, or arid climates, dries out nasal mucus and causes the membrane to crack. You get a scab, you feel it and pick at it, the scab tears away and bleeds, a new scab forms, and the cycle repeats. People who use supplemental oxygen are especially prone to this dryness. If petroleum jelly is your go-to moisturizer, be aware that petroleum-based products should not be used around the nose during oxygen therapy; water-based gels or oil-in-water creams are safer alternatives in that setting.6PubMed. Safety in the use of vaseline during oxygen therapy: the pharmacist’s perspective For everyone else, a thin layer of petroleum jelly or saline gel inside the nostrils at bedtime can help keep the lining from cracking overnight.
Nasal Sprays and Other Medications
Over-the-counter decongestant sprays (oxymetazoline, phenylephrine) are notorious for causing rebound congestion when used beyond a few days, and that cycle of repeated use can damage nasal tissue. But prescription nasal sprays can also contribute to sores. Steroid sprays used for allergies sometimes irritate the septum if the spray nozzle is aimed directly at it rather than toward the outer wall of the nostril. Over time, this localized irritation can thin the tissue and, in uncommon cases, lead to a perforation of the nasal septum.7PubMed. Pathophysiology and progression of nasal septal perforation Septal perforations can also result from cocaine use, certain autoimmune diseases, and prior nasal surgery, but the most common cause overall is iatrogenic, meaning related to medical treatment or procedures.
If you use a nasal steroid spray daily for allergies, point the nozzle slightly away from the center wall of your nose and alternate nostrils. A burning or crusting sensation on the septum is a sign you may need to adjust your technique or talk to your doctor about lowering the dose.
Contact Allergies From Topical Products
Sometimes the very products you use to treat a nasal sore make things worse. Neomycin, an antibiotic found in many over-the-counter triple-antibiotic ointments, is a common contact allergen. A large meta-analysis covering hundreds of thousands of patch-tested patients found that about three percent of adults and four percent of children had a contact allergy to neomycin, with rates running highest in North America, where roughly six percent of adults tested positive.8PubMed Central. Prevalence of Contact Allergy to Neomycin in Dermatitis Patients: A Systematic Review and Meta‐Analysis If you apply a neomycin-containing ointment to a sore inside your nose and the irritation gets worse rather than better, the ointment itself could be the problem. Switching to a product without neomycin, or using plain petroleum jelly for moisture, often resolves the reaction.
Fungal Infections
We all inhale fungal spores with every breath, and for most people this is harmless. Fungal infections inside the nose tend to become a problem mainly in people whose immune systems are weakened, whether from uncontrolled diabetes, chemotherapy, organ transplant medications, or HIV. The spectrum of fungal nasal disease ranges from mild sinus symptoms to aggressive tissue invasion that can spread toward the brain.9PubMed Central. The role of fungi in diseases of the nose and sinuses The most feared form, invasive mucormycosis (sometimes called “black fungus”), destroys tissue rapidly and requires emergency treatment.
For an otherwise healthy person, a nasal sore caused by fungus is unlikely. But if you are immunocompromised and develop a dark, painful lesion inside the nose that spreads quickly or comes with numbness of the face, seek care immediately. Time matters with invasive fungal infections in a way it does not with ordinary bacterial sores.
Autoimmune and Inflammatory Diseases
Persistent, non-healing nasal sores occasionally point to a systemic condition rather than a simple infection. Granulomatosis with polyangiitis (GPA, formerly known as Wegener’s granulomatosis) is a rare autoimmune disease that attacks blood vessels and commonly affects the nose, sinuses, lungs, and kidneys. In the nose, GPA can produce crusting, bloody discharge, and ulcers that do not respond to antibiotics. Nasal endoscopy in suspected GPA has revealed characteristic lesions including white submucosal nodules, bloody patches, and polypoid nodules, several of which had high diagnostic accuracy for the disease when biopsied.10PubMed. Increased histopathological yield for granulomatosis with polyangiitis based on nasal endoscopy of suspected active lesions
Distinguishing GPA from other causes of destructive nasal lesions is tricky. Cocaine use, certain lymphomas, and infections like tuberculosis can all produce tissue destruction in the midface that looks similar on examination. Clinicians typically work through an extensive panel of blood tests, imaging, cultures, and biopsies to sort these apart.11PubMed. The dilemma of midline destructive lesions: a case series and diagnostic review One useful clinical clue: a perforation of the palate (the roof of the mouth) alongside nasal destruction tends to favor cocaine-induced damage over GPA when blood tests and biopsy results are inconclusive.12PubMed Central. Palate perforation differentiates cocaine-induced midline destructive lesions from granulomatosis with polyangiitis These are rare diagnoses, but any nasal sore that persists for weeks, keeps getting worse, or is accompanied by symptoms elsewhere in the body (joint pain, blood in the urine, cough) warrants a thorough workup.
Foreign Bodies in Children
Young children are reliably creative about putting things in their noses, and a forgotten foreign body is a surprisingly common cause of a foul-smelling, one-sided nasal discharge that parents sometimes mistake for a stubborn sinus infection. Objects range from beads and food to more dangerous items like button batteries. A case involving a five-year-old girl documented a button battery impacted against the nasal septum, causing blockage, bleeding, and foul-smelling discharge within just one day.13PubMed Central. The hazards of impacted alkaline battery in the nose Button batteries are particularly harmful because they generate an electrical current against moist tissue, which can burn through the septum in hours.
If your child develops a smelly discharge from one nostril, especially if there is no fever or other signs of a typical cold, suspect a foreign body. This is not a wait-and-see situation, particularly if a battery could be involved. A visit to the emergency room or an ear-nose-throat specialist for removal is the right move.
How the Nasal Microbiome Plays a Role
Your nose is not a sterile environment; it hosts a community of bacteria, fungi, and other microbes that, when balanced, actually help protect the lining from infections. When that microbial balance is disrupted, a condition researchers call dysbiosis, the immune response in the nose can malfunction and the protective barrier of the lining weakens, setting up a cycle of inflammation that makes sores more likely and slower to heal.14PubMed. The Nasal Microbiome in Inflammation and Disease: Bridging Mechanisms to Therapeutics Bacterial biofilms, tough communities of bacteria that cling to surfaces and resist antibiotics, can form inside the nose and contribute to sores that keep coming back despite treatment.
This helps explain why some people get recurrent nasal sores while others never do. Chronic nasal Staph carriers, people with frequent antibiotic use, and those with chronic sinus inflammation may all have disrupted nasal microbiomes that leave their nasal lining more vulnerable. It also explains why simply killing off bacteria with antibiotics does not always solve the problem; restoring the overall microbial environment matters too.
Treating Nasal Sores at Home
Most simple nasal sores respond well to basic care. Keeping the inside of the nose moist is the single most helpful step. A saline nasal spray or rinse loosens crusts without irritating the tissue, and applying a thin layer of petroleum jelly (or a water-based nasal gel if you are on oxygen) to the inside of the nostrils before bed prevents overnight drying. Resist the urge to pick at scabs; they are part of the healing process, and pulling them off restarts the bleeding-scabbing cycle.
For sores that look or feel infected, with spreading redness, increasing pain, or yellow-green discharge, mupirocin ointment applied inside the nostrils is the standard first-line treatment. Mupirocin is effective at clearing Staph aureus from the nose: a Cochrane review pooling eight studies found that it cut the rate of Staph infection by about 45 percent compared with placebo or no treatment.15Cochrane Database of Systematic Reviews. Mupirocin nasal ointment for eliminating nasal carriage of Staphylococcus aureus It also significantly reduced the number of people carrying the bacteria overall.16PubMed Central. Effect of mupirocin treatment on nasal, pharyngeal, and perineal carriage of Staphylococcus aureus in healthy adults Mupirocin requires a prescription in most places, so you will need to see a provider to get it. Over-the-counter antibiotic ointments work for many mild cases, but keep the neomycin allergy risk in mind if irritation worsens after application.
When to See a Doctor
A small scab or pimple inside the nose that heals within a week or two is almost never worth a doctor visit. But certain patterns should prompt you to make an appointment or, in some cases, go to urgent care:
- Spreading redness or swelling: If the skin around or between your nostrils becomes red, warm, and puffy, the infection may be spreading beyond the initial sore. A growing boil on the tip or side of the nose needs medical evaluation because of the venous drainage risk described earlier.
- Fever with a nasal sore: A fever alongside a painful nasal lesion suggests the infection may have moved beyond a local problem. This is especially urgent in anyone with a weakened immune system.
- A sore that will not heal for more than three weeks: Persistent non-healing lesions raise the possibility of autoimmune disease, fungal infection, or, rarely, nasal cancer. A biopsy is usually needed to sort out the cause.
- One-sided foul discharge in a child: Think foreign body until proven otherwise.
- Recurrent blistering sores: If clusters of small blisters keep returning in the same area, a herpes simplex diagnosis can be confirmed with a swab, and antiviral treatment can reduce the frequency and severity of outbreaks.
- Dark or rapidly spreading tissue damage: A black or dark-colored lesion inside the nose that grows quickly, especially with facial numbness or pain, could indicate an invasive fungal infection and requires emergency care.
- Accompanying systemic symptoms: Joint pain, bloody urine, persistent cough, unexplained weight loss, or skin rashes alongside nasal sores raise the possibility of a vasculitis like GPA or another systemic disease. These combinations call for prompt evaluation.
Why Some People Get Nasal Sores Repeatedly
Recurrent nasal sores are frustrating, and the reason is often a combination of factors rather than one simple cause. About a third of healthy adults carry Staph aureus in their nostrils at any given time, and these persistent carriers are more prone to recurrent vestibulitis whenever the nasal lining gets disrupted. Treating the active sore with mupirocin clears the infection, but the bacterium often recolonizes from the throat or skin within months.16PubMed Central. Effect of mupirocin treatment on nasal, pharyngeal, and perineal carriage of Staphylococcus aureus in healthy adults That recolonization, combined with the microbiome disruption cycle mentioned earlier, helps explain why some people deal with these sores season after season.
Practical steps that reduce recurrence include keeping the nasal lining moisturized (saline rinses, humidifiers during winter), not picking or pulling at nasal hairs, aiming steroid spray nozzles away from the septum, and washing hands before touching the face. For people who get frequent infected sores, a doctor may prescribe a course of mupirocin specifically aimed at reducing Staph carriage, sometimes paired with chlorhexidine body washes to lower the overall bacterial load on the skin. The evidence behind these decolonization protocols is solid for preventing surgical-site infections in hospital settings, and many providers apply the same logic to recurrent nasal infections in outpatients.