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Health condition · Clinically reviewed

Lip and mouth skin problems, explained and treated.

Cracked mouth corners, cold sores, a rash around the mouth, or lips that will not stop peeling - each has a distinct cause and a clear treatment path.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against NICE, BAD and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK guidance on angular cheilitis, cold sores, perioral dermatitis and cheilitis.

Key facts

Lip and perioral skin conditions at a glance.

The essentials, in plain English - what each condition is, and how it differs from the others covered here.

  • What it covers

    A group of conditions affecting the lips and skin around the mouth - not the inside of the mouth or the tongue.

  • Angular cheilitis

    Cracked, sore corners of the mouth, often driven by candida, saliva pooling or an underlying nutritional deficiency.

  • Cold sores

    Herpes labialis - recurrent, painful vesicular clusters caused by herpes simplex virus type 1.

  • Perioral dermatitis

    A papular rash around the mouth, commonly triggered or worsened by topical steroid overuse.

  • Cheilitis

    Lip inflammation from irritants, sun exposure, allergy or licking - dry, scaling or swollen lips.

  • Not covered here

    Oral mucosal disease and cancer risk inside the mouth are covered separately in our oral pathologies guide.

Why this guide matters

Four look-alikes, four different treatments.

Problems around the mouth are often lumped together as "chapped lips" - but the right treatment depends on getting the diagnosis right first.

  • Location and appearance narrow it down

    Cracked corners, a papular rash, vesicular clusters and generalised dryness each point to a different underlying cause.

  • Steroid creams can make things worse

    Perioral dermatitis is frequently triggered or prolonged by the very steroid cream reached for to calm it down.

  • Most cases settle with the right first step

    An antifungal, an antiviral, a tetracycline course or simply stopping an irritant - most of these conditions respond quickly once correctly identified.

How the diagnosis is made

From a sore mouth to a confirmed diagnosis.

The steps a UK GP or dermatologist will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History and pattern

    When it started, whether it recurs, and any triggers - lip-licking, dentures, new products, steroid creams.

  2. 02

    Assessing

    Examination of lips and skin

    Looking at distribution - corners of the mouth, vermilion border, or a papular rash spreading outward from the mouth.

  3. 03

    Assessing

    Denture and appliance check

    Ill-fitting dentures or braces can create the moist folds where angular cheilitis thrives.

  4. 04

    Confirming

    Swabs if infection suspected

    Bacterial, fungal or viral swabs help confirm candida, staphylococcus or herpes simplex as the driver.

  5. 05

    Confirming

    Patch testing for allergy

    Reserved for suspected allergic contact cheilitis - lip balm, toothpaste, sunscreen or cosmetic ingredients.

  6. 06

    Preparing

    Nutritional bloods when needed

    Iron and B12 checked in angular cheilitis with no obvious local cause, particularly if recurrent.

  7. 07

    Preparing

    Dermatology referral if unclear

    Persistent or atypical presentations, or failure of first-line treatment, warrant a specialist opinion.

Typical timeline: a single GP visit to a working treatment plan, often the same day.

Symptoms

What these conditions actually look like.

The presentation varies widely - from cracked corners to a spreading rash. And the features that mean it's time to be seen urgently.

  • Cracked mouth corners

    Angular cheilitis - soreness, fissuring and sometimes bleeding at the corners of the mouth, often bilateral.

  • Painful vesicular clusters

    Cold sores begin as tingling, then form grouped fluid-filled blisters that crust over within days.

  • Papular perioral rash

    Perioral dermatitis - small red or skin-coloured bumps clustered around the mouth, sparing a narrow rim near the lips.

  • Dry, scaling lips

    Cheilitis from irritants or weather - flaking, tightness and visible dryness across the lip surface.

  • Sun-related lip changes

    Actinic cheilitis - persistent scaling or a rough patch on the lower lip from cumulative sun exposure.

  • Swollen or angry lips

    Allergic or irritant cheilitis can cause visible swelling alongside redness and discomfort.

  • Recurrent flares

    Both cold sores and perioral dermatitis tend to recur, often triggered by stress, sun or product changes.

  • Red flag - non-healing lip lesion

    A lip sore or ulcer that will not heal within three weeks needs urgent assessment, not home treatment.

Treatment

How each condition is treated in the UK.

Treating the underlying cause, protecting the lip barrier, and avoiding the irritants and habits that keep flares going.

  • Topical antifungal

    Clotrimazole or miconazole cream for candida-driven angular cheilitis - usually combined with a barrier ointment.

  • Denture and fit correction

    Refitting ill-fitting dentures reduces the moist skin folds that let angular cheilitis persist and recur.

  • Nutritional correction

    Iron or B12 replacement where deficiency is found and contributing to recurrent angular cheilitis.

  • Topical antiviral cream

    Aciclovir or penciclovir cream started at the first tingle can shorten a cold sore episode.

  • Oral antiviral therapy

    Aciclovir or valaciclovir tablets for frequent, severe or immunocompromised cold sore episodes.

  • Stopping topical steroids

    The essential first step in perioral dermatitis, even though symptoms often flare briefly before improving.

  • Oral tetracycline course

    Doxycycline or lymecycline for several weeks is the mainstay treatment for persistent perioral dermatitis.

  • Lip barrier and sun protection

    Plain emollient balms and a lip SPF reduce irritant and actinic cheilitis and support healing between flares.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or dermatologist knows your skin and history and can tell you which parts apply to you. If in doubt, get seen.

  • NICE CKS. Angular cheilitis, cold sores and perioral dermatitis - clinical knowledge summaries.

  • British Association of Dermatologists (BAD). Patient information leaflets on perioral dermatitis and cheilitis.

  • British Association for Sexual Health and HIV (BASHH) and PHE. Herpes simplex virus management.

  • Primary Care Dermatology Society (PCDS). Lip and perioral skin condition guidance.

Red flags

When a lip or mouth problem needs urgent attention.

Most of these conditions are manageable in primary care. These are the situations that aren't - and where urgent or specialist input is needed.

  • Non-healing lip ulcer

    Any lip lesion or ulcer present beyond three weeks needs urgent assessment to exclude skin cancer.

  • Eczema herpeticum

    Widespread painful blistering on eczema-prone skin near cold sores is a dermatological emergency.

  • Immunosuppression with cold sores

    Severe, widespread or unusually persistent herpes simplex in an immunosuppressed patient needs prompt specialist input.

  • Herpes simplex near the eye

    Vesicles spreading toward the eye risk ocular herpes and need same-day ophthalmology assessment.

  • Angioedema

    Rapid lip and facial swelling with breathing difficulty is an emergency - call 999.

  • Suspected skin cancer of the lip

    A firm, growing, ulcerated or bleeding lip lesion warrants urgent two-week-wait dermatology referral.

  • Severe allergic reaction

    Lip swelling with hives, tongue swelling or difficulty swallowing needs emergency care.

  • Recurrent unexplained deficiency signs

    Angular cheilitis alongside fatigue, pallor or glossitis warrants a fuller nutritional and haematology work-up.

  • Steroid dependency

    A perioral rash that rebounds every time a steroid cream is stopped needs a supervised withdrawal plan.

Living with it

Simple habits, fewer flares.

Four things that make the biggest difference day to day - lip protection, sun care, spotting your own triggers, and resisting the leftover steroid cream.

A quiet reminder

A plain barrier balm beats a medicine cabinet of products.

Fewer, simpler products around the lips and mouth reduce the chance of irritation and allergic reactions.

  1. 01 Protect

    Use a plain lip balm daily

    A simple, fragrance-free barrier balm protects lips from wind, cold and licking - avoid flavoured or medicated balms that can irritate.

  2. 02 Sun

    Apply lip SPF

    Cumulative sun exposure drives actinic cheilitis - a lip balm with SPF is a small habit with a real payoff.

  3. 03 Trigger

    Track your flares

    Note what precedes a cold sore or perioral dermatitis flare - sun, stress, a new product - and adjust accordingly.

  4. 04 Avoid

    Stop self-treating with steroid cream

    Reaching for a leftover steroid cream on a perioral rash usually makes things worse - see a clinician instead.

Frequently asked

Everything we get asked about lip and mouth skin problems.

Quick answers on angular cheilitis, cold sores, perioral dermatitis and cheilitis.

  • What counts as an oral or perioral skin condition?

    This guide covers conditions affecting the lips and the skin around the mouth - angular cheilitis, cold sores, perioral dermatitis and cheilitis. It does not cover disease inside the mouth itself, such as oral mucosal lesions or cancer risk, which are addressed in our oral pathologies guide.

  • Why do the corners of my mouth keep cracking?

    This is usually angular cheilitis, often caused by candida thriving in the moist skin fold at the mouth corner. Ill-fitting dentures, excess saliva pooling and iron or B12 deficiency are common contributing factors.

  • How do I stop getting cold sores so often?

    Frequent recurrence is common because herpes simplex virus remains dormant in nerve tissue. Starting antiviral cream at the first tingle, using daily sun protection on the lips, and managing stress can reduce frequency, and oral antivirals are an option for very frequent episodes.

  • Is perioral dermatitis caused by steroid cream?

    Topical steroid overuse - even mild strengths used on the face for other reasons - is a well-recognised trigger. Treatment means stopping the steroid, which can cause a temporary flare, alongside a course of oral tetracycline.

  • What is the difference between cheilitis and chapped lips?

    Ordinary chapped lips settle quickly with a barrier balm. Cheilitis is more persistent inflammation from an irritant, allergy or sun exposure, and it can need patch testing or a change in products if it does not resolve.

  • When should I see a doctor about a lip problem?

    See a clinician if a lip lesion has not healed within three weeks, if a rash keeps recurring despite simple measures, if you suspect an allergy, or if there is swelling affecting breathing or swallowing, which needs emergency care.

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