Skin Ulcer (Open Sore)

What a skin ulcer is

Skin heals in an orderly way: bleeding stops, inflammation clears debris, new tissue fills the gap, and skin grows across. An ulcer forms when something blocks this process: too little oxygen, constant pressure, high sugar, infection, ongoing inflammation or abnormal cells. Unlike a scrape, an ulcer usually has visible depth, and the base may show red granulation tissue, yellow slough or black dead tissue.

Types of skin ulcers and how to tell them apart

Non-healing leg and foot wounds are covered in more depth on the chronic ulcer page.

Open sores in the nose and on the face

Sores in the nostril or on the nose are common and usually minor, but they can be stubborn because the area is moist, picked and full of bacteria.

Common causes of an open sore in the nostril

• Picking and nose blowing: small cracks become scabs that are picked again, so they never heal.
• Dry air: winter heating, oxygen tubing and CPAP dry the lining.
• Nasal vestibulitis: a bacterial infection, usually staph, of the skin just inside the nostril. Red, tender, crusted, sometimes with a pimple-like bump.
• Cold sores (herpes simplex): tingling then clustered blisters, often at the nostril edge.
• Nasal sprays and drugs: steroid sprays aimed at the septum, and snorting cocaine or other drugs.
• Allergic or irritant reactions to tissues or creams.
• Less often: a perforated septum, granulomatosis with polyangiitis (crusting and bleeding with sinus symptoms), or skin cancer.

How to treat an open sore on the nose

1. Stop picking. Trim fingernails and use a tissue to blot rather than wipe.
2. Keep it moist: apply a thin layer of petroleum jelly inside the nostril 2 to 3 times a day.
3. Saline spray or gel to moisten the lining; use a humidifier at night.
4. If it looks infected (crusting, swelling, increasing pain): a clinician may prescribe an antibiotic ointment such as mupirocin.
5. Cold sores: start an over-the-counter cold sore cream at the first tingle; prescription antiviral tablets help frequent outbreaks.
6. Pain relief: acetaminophen (paracetamol) or ibuprofen, following the label dose.

See a doctor if a sore on the nose spreads, causes facial swelling or fever, or has not healed within 4 weeks. A sore on the outside of the nose that bleeds, crusts and returns is a classic presentation of basal cell carcinoma, which is easily treated when found early.

How skin ulcers are diagnosed

• History and examination: location, duration, pain, appearance of the edges and base, and the surrounding skin.
• Ankle-brachial index (ABI): compares blood pressure in the ankle and arm to check for blocked arteries; done before using compression.
• Vein ultrasound: for suspected venous disease.
• Blood tests: sugar (HbA1c), blood count, kidney function and inflammatory markers.
• Wound swab: only if there are signs of infection; all ulcers carry surface bacteria.
• X-ray or MRI: if bone infection (osteomyelitis) is suspected, especially in diabetic foot ulcers.
• Biopsy: for ulcers that look unusual or have not healed in 6 to 12 weeks despite good care.

Treatment

Treat the cause

• Venous ulcers: compression bandages or stockings are the main treatment, plus leg elevation and walking; vein procedures reduce recurrence.
• Arterial ulcers: restoring blood flow with angioplasty or bypass. Compression is not used.
• Diabetic foot ulcers: offloading pressure with special boots or casts, blood sugar control and regular podiatry.
• Pressure ulcers: repositioning, pressure-relieving mattresses and cushions, nutrition.
• Inflammatory ulcers: steroids or immune-suppressing treatment.

Wound care

• Clean gently with saline or clean water at each dressing change.
• Keep the wound moist (not wet) with an appropriate dressing; dry wounds heal more slowly.
• Remove dead tissue (debridement) when needed.
• Protect surrounding skin with barrier creams.
• Avoid harsh antiseptics such as hydrogen peroxide on healing tissue.

Support healing

Stop smoking, eat enough protein, control blood sugar, stay active, and treat swelling.

Frequently asked questions

What causes a skin ulcer?

Most skin ulcers are caused by poor blood flow in the veins or arteries, diabetes with nerve damage, or prolonged pressure on the skin. Others result from infections, inflammatory diseases, injuries that are repeatedly picked or rubbed, and skin cancer. The cause determines the treatment.

Why won't the sore in my nostril heal?

Common reasons are repeated picking or nose blowing, dry air, a low-grade staph infection (nasal vestibulitis) or recurrent cold sores. Keeping the area moist with petroleum jelly and leaving it alone often helps within 1 to 2 weeks. A sore persisting beyond 4 weeks should be examined.

How do I treat an open sore on my nose?

Stop picking, keep the sore moist with petroleum jelly, use saline spray and a humidifier, and take simple pain relief if needed. If it becomes crusted, swollen and tender, a doctor may prescribe mupirocin ointment. Cold sores respond to antiviral creams or tablets.

When should I worry about a sore that won't heal?

See a doctor if a sore has not healed in 4 weeks, keeps bleeding or scabbing in the same spot, is growing, has a raised or pearly edge, or occurs on the feet of someone with diabetes. Fever, spreading redness or severe pain need prompt care.

Can a skin ulcer be cancer?

Some can. Basal cell and squamous cell carcinomas often look like a sore that crusts, bleeds and never fully heals, especially on sun-exposed skin. Long-standing ulcers and scars can also rarely turn cancerous. A biopsy is the only way to be sure.