Efudix cream (5‑fluorouracil) for actinic keratosis and Bowen’s disease

Efudix cream (5‑fluorouracil) is a prescription “field treatment” cream commonly used in Australia for actinic keratosis (solar keratosis) and squamous cell carcinoma in situ (SCC in situ / Bowen’s disease / intraepidermal carcinoma).

Efudix cream (5‑fluorouracil) works well — but it can be uncomfortable and visually dramatic during treatment. This page explains how Efudix cream (5‑fluorouracil) works, how to apply it safely, what the reaction typically looks like, and when to contact your doctor.

If you’re unsure the diagnosis is correct, the spot is changing, or you want to discuss alternatives (including laser‑assisted photodynamic therapy (PDT) or Aldara cream (imiquimod)), book a skin cancer consultation(automed : 20 minute appointment with Dr Chris). (1)

Key takeaways

Efudix cream (5‑fluorouracil) targets fast‑dividing precancer/cancer cells more than normal skin cells.
Typical treatment lengths are often 4 weeks for actinic keratosis and around 6 weeks for SCC in situ / Bowen’s disease — but your doctor’s plan comes first. (2)
The reaction from Efudix cream (5‑fluorouracil) often starts mildly, then becomes red, sore, crusted and sometimes oozy from about day 5–7 onward.
Many patients using Efudix cream (5‑fluorouracil) on the face take 2–4 weeks off work (timing varies).
Avoid getting Efudix cream (5‑fluorouracil) near eyes, nostrils, lips, or other sensitive sites unless your treating doctor has given specific instructions.

What is Efudix cream (5‑fluorouracil)?

Efudix cream (5‑fluorouracil) is a topical chemotherapy cream used to treat sun‑damaged skin cells. In the USA, the same medicine is commonly spelled Efudex cream (5‑fluorouracil).

What does Efudix cream (5‑fluorouracil) treat?

Efudix cream (5‑fluorouracil) is most commonly used for:

Actinic keratosis (solar keratosis) — a sun‑damage “precancer” (3)
Squamous cell carcinoma in situ (also called Bowen’s disease or intraepidermal carcinoma) (4)

Doctors may sometimes prescribe Efudix cream (5‑fluorouracil) for other conditions, but this should be guided by a clinician experienced with Efudix cream (5‑fluorouracil).

Quick comparison

Comparison of Efudix to other field actinic keratosis treatments (Jump to table 1 below Field Treatment Comparison: Actinic Keratosis (AK))

Comparison of Efudix to other non melanoma skin cancer treatments (jump to table 2 below)

How Efudix cream (5‑fluorouracil) works

Efudix cream (5‑fluorouracil) blocks an enzyme (thymidylate synthetase) that cells need to make DNA. Cells that are dividing need to make new DNA — so Efudix cream (5‑fluorouracil) preferentially damages rapidly dividing abnormal cells (like actinic keratoses and SCC in situ) compared with normal skin cells.

How effective is Efudix cream (5‑fluorouracil)?

Effectiveness depends on the diagnosis, how consistently Efudix cream (5‑fluorouracil) is applied, the treatment duration, and the individual.

For actinic keratosis, Efudix cream (5‑fluorouracil) is one of the most effective field therapies. In many studies and clinical experience, it can produce strong clearance across treated areas for many months. (2)
For SCC in situ (Bowen’s disease), published cure rates vary widely (often quoted in the range of ~50–85% depending on factors such as duration and lesion characteristics). (2)

If you want the highest certainty of cure (particularly for higher‑risk sites/lesions), discuss alternatives such as laser‑assisted photodynamic therapy (PDT) (5, 6) or procedural options with your doctor.

Your treatment plan for Efudix cream (5‑fluorouracil)

Your clinician will tailor your course, but typical patterns include:

Actinic keratosis: often 3–4 weeks of Efudix cream (5‑fluorouracil)
SCC in situ (Bowen’s disease): often around 6 weeks of Efudix cream (5‑fluorouracil)

Do not change the length of Efudix cream (5‑fluorouracil) treatment without advice — shortening can reduce effectiveness, and extending can increase discomfort and irritation.

Where to apply Efudix cream (5‑fluorouracil)

Efudix cream (5‑fluorouracil) is usually applied:

directly to the diagnosed lesion, plus a margin (commonly about 5 mm, but follow your doctor’s instruction)

Because Efudix cream (5‑fluorouracil) can irritate normal skin, accuracy matters — especially near eyes, lips, nostrils, genitals, and skin folds.

How to apply Efudix cream (5‑fluorouracil) safely

Step‑by‑step

Wash the skin with warm water (avoid soap unless your doctor advises otherwise).
Pat dry, then wait 10–15 minutes.
Apply Efudix cream (5‑fluorouracil) to the area your doctor advised (lesion + margin).
- Use a disposable nitrile glove or an applicator.
Avoid mucous membranes (eyes, inside the nose, lips). If the treatment area is close to these, get specific instructions before starting Efudix cream (5‑fluorouracil).
Wash hands thoroughly after application (even if you used a glove).
Do not cover the area unless your doctor tells you to.
- Occlusive dressings can increase the reaction and side effects.
- If you need to cover for cosmetic reasons, a non‑occlusive porous gauze may be an option — discuss this with your doctor first.
After about 20 minutes, you can usually apply moisturiser, sunscreen, and/or make‑up as part of your routine. (7)
Efudix cream (5‑fluorouracil) can take up to 2 hours to absorb — apply evening Efudix cream (5‑fluorouracil) 2–3 hours before bed to reduce rubbing onto bedding.

Area limit

Do not treat an area larger than about 23 × 23 cm with Efudix cream (5‑fluorouracil) unless your doctor has specifically planned this.

How much Efudix cream (5‑fluorouracil) should I use?

The amount of Efudix cream (5‑fluorouracil) depends on the area being treated.

A practical guide many clinicians use:

Start with a pea‑sized amount of Efudix cream (5‑fluorouracil) and spread it thinly.
For “full face field treatment” with Efudix cream (5‑fluorouracil), some patients use multiple pea‑sized amounts to cover each facial zone — but the exact dose and whether full‑face treatment is appropriate must be confirmed by your treating doctor.

What to expect on Efudix cream (5‑fluorouracil)

Efudix cream (5‑fluorouracil) is often described as one of the most uncomfortable topical skin treatments. The reaction can look alarming even when it’s “normal” for Efudix cream (5‑fluorouracil).

A common pattern is:

Days 1–5: mild redness, dryness, mild sting
Days 5–14: increasing redness, burning/tenderness, swelling; discomfort increases
Weeks 2–6 (depending on course): peak inflammation — cracking, crusting, and sometimes ooze
After stopping Efudix cream (5‑fluorouracil): healing usually takes a few weeks for the skin to settle back toward normal

Many people using Efudix cream (5‑fluorouracil) on the face find facial movement (talking, eating, laughing) can be painful during the peak phase.

Comfort and skin care during Efudix cream (5‑fluorouracil)

If you’re struggling, contact your doctor — there are ways to make Efudix cream (5‑fluorouracil) more tolerable, but some changes can reduce effectiveness.

General strategies often include:

Moisturiser after Efudix cream (5‑fluorouracil) has had time to absorb (often after ~20 minutes)
Sun protection and sensible sun avoidance (7)
Planning social/work downtime if you’re treating a visible area (common for face treatments)

Common side effects of Efudix cream (5‑fluorouracil)

Common and expected local effects include:

redness, burning, stinging
swelling and tenderness
crusting/scabbing
cracking and oozing
sensitivity to heat and wind

These are often part of the intended inflammatory response of Efudix cream (5‑fluorouracil).

Less common risks of Efudix cream (5‑fluorouracil)

Pigment changes (hyperpigmentation or hypopigmentation)

Inflammation from Efudix cream (5‑fluorouracil) can sometimes trigger pigment changes (darker or lighter patches). Permanent changes appear rare in many clinicians’ experience, but the risk is not zero — and may be higher if you already have pigmentation conditions.

Scarring

Efudix cream (5‑fluorouracil) causes significant inflammation, so scarring is possible (though uncommon). If scarring occurs, it can often be improved with scar‑focused treatments — discuss this before starting if you’re concerned.

Worsening facial redness (rosacea / telangiectasia)

In some patients, inflammation from Efudix cream (5‑fluorouracil) can worsen background redness or visible small vessels. If you have rosacea‑prone skin, discuss this risk and alternatives before starting.

Non‑healing ulcer (especially lower legs)

Lower legs can heal more slowly due to poorer circulation. If you’re using Efudix cream (5‑fluorouracil) on the lower leg, monitor carefully and stay in touch with your doctor if the area doesn’t heal as expected.

Infection

True bacterial infection after Efudix cream (5‑fluorouracil) is uncommon in many clinicians’ experience, but it can occur. The challenge is that normal Efudix cream (5‑fluorouracil) reactions can look “infected” (red, oozy, crusted). If you’re unsure, seek review promptly.

Who should not use Efudix cream (5‑fluorouracil)?

Efudix cream (5‑fluorouracil) should not be used if you are:

pregnant
trying to conceive
breastfeeding

Always tell your doctor about your medical history and medicines before starting Efudix cream (5‑fluorouracil).

Rare but serious toxicity from Efudix cream (5‑fluorouracil)

Life‑threatening toxicity from topical Efudix cream (5‑fluorouracil) is extremely rare, but it’s important to know the red flags.

Seek urgent medical care if you develop symptoms such as:

severe abdominal pain/cramps, vomiting, or bloody diarrhoea
swelling/soreness of the mouth or tongue
fevers and chills (flu‑like illness)
feeling severely unwell in a way that seems out of proportion to a local skin reaction

DPD deficiency and Efudix cream (5‑fluorouracil)

A small number of people have dihydropyrimidine dehydrogenase (DPD) deficiency, which can reduce the body’s ability to break down Efudix cream (5‑fluorouracil). This may increase the risk of toxicity.

If you or a family member has known DPD deficiency, tell your doctor before using Efudix cream (5‑fluorouracil). Routine testing is not commonly done in Australia before starting Efudix cream (5‑fluorouracil), but your doctor can advise based on your situation.

Alternatives to Efudix cream (5‑fluorouracil)

If Efudix cream (5‑fluorouracil) doesn’t suit your lifestyle, pain tolerance, skin type, or lesion pattern, alternatives may include:

Laser‑assisted photodynamic therapy (PDT) for actinic keratosis (solar keratosis) (5)
Laser‑assisted photodynamic therapy (PDT) for selected non‑melanoma skin cancers (6)
Aldara cream (imiquimod) for selected lesions and situations (8)
lesion‑directed options such as cryotherapy or procedural removal (guided by diagnosis and risk)

A consultation helps match the right treatment to your diagnosis, body site, downtime tolerance, and desired certainty of clearance. (1)

Field Treatment Comparison: Actinic Keratosis (AK): At-a-Glance

Feature	LA-PDT (Laser-Assisted)	Efudix (5-fluorouracil)	Aldara (imiquimod)
Indicated For	Multiple/Field AKs	Multiple/Field AKs	Multiple/Field AKs
Effectiveness	~90-95% clearance; highly effective for thick lesions.	~75% full clearance of visible lesions.	~70% – 85% clearance.
Delivery	In-clinic, doctor-led	At-home, self-applied	At-home, self-applied
Mechanism	Laser ablation + light-activated cell death .	Topical chemotherapy; blocks DNA synthesis.	Immune system stimulant; triggers local attack.
Visible Reaction	Intense redness, crusting, and swelling (brief).	Significant redness, erosion, and “angry” scabbing.	Redness, weeping, and localized inflammation.
Systemic (Whole Body) Side Effects	None	5–10% can develop flu-like illness, cramps, vomiting, or alopecia. Rare bone marrow suppression (life-threatening if DPD deficient).	5–10% can develop flu-like illness, headaches, dizziness, or fatigue.
Discontinuation (Severe Side Effects)	None	~5% stop early due to severe reactions or pain.	~3% stop early due to systemic or local reactions.
Downtime	Short: 7–10 days for most healing.	Prolonged: 4–8 weeks (treatment + healing).	Prolonged: 4–8 weeks (treatment + healing).
Cosmetic Outcome	Excellent: Often improves overall skin texture.	Good: Slightly higher risk of pigment changes or scarring. Also worsens rosacea.	Good: Slightly higher risk of pigment changes or scarring. Also worsens rosacea.

Table 1.

Treatment Comparison comparing Efudix to other options for non melanoma skin cancer (NMSC): At-a-Glance

Feature	LA-PDT (Laser-Assisted)	Surgery	Efudix (5-fluorouracil)	Aldara (imiquimod)
Indicated For	sBCC, SCCis, nBCC* (10-15)	sBCC, SCCis, nBCC*	SCCis (3)	sBCC (2)
Effectiveness	~94% – 100% ((10-14))	~97%	70% (8)	~80% (non-facial); 42–76% (facial) (9)
Delivery	In-clinic, doctor-led	In-clinic	At-home, self-applied (3)	At-home, self-applied (2)
Typical Course	1–2 sessions	1 session	Twice daily for 6 weeks	5 days a week for 6 weeks
Mechanism	Laser ablation + light-activated cell death	Surgical excision	Topical chemotherapy (3)	Immune system stimulant (2)
Visible Reaction	Red, weeping area	Scarring	Red, weeping area	Red, weeping area
Systemic (whole body) side effects	None	None	5-10% can develop flu like illness, abdominal cramps, persistent vomiting, bloody diarrhoea, alopecia, rare bone marrow suppression. Very rarely life threatening (18,19).	5-10% can develop Flu like illness, headaches, dizziness, insomnia, diarrhoea(16,17,19).
Discontinuation before treatment complete due to severe side effects	None	None	5% (19)	3% (19)
Downtime	Short (days)	Weeks – 3 months (dependent on area and size)	Prolonged (weeks- two months)	Prolonged (weeks-two months
Cosmetic Outcome	Excellent (10-14)	Good (dependent on area and size)	Good (risk of pigment changes)	Good (risk of pigment changes)

Table 2. *nBCC indication for LA-PDT may be considered off-label depending on clinical selection (36).

Frequently asked questions

Does Efudix cream (5‑fluorouracil) mean I have skin cancer?

Efudix cream (5‑fluorouracil) is used for both precancers (actinic keratosis) and very early skin cancers confined to the top layer (SCC in situ / Bowen’s disease). If you’re unsure what your diagnosis is, ask your treating doctor to clarify (and consider a second opinion if needed). (1)

How long will I look “normal” after Efudix cream (5‑fluorouracil)?

After finishing Efudix cream (5‑fluorouracil), most people take a few weeks for the skin to settle. Facial treatments often take longer than small spot treatments.

Can I wear sunscreen or make‑up over Efudix cream (5‑fluorouracil)?

Many people apply moisturiser, sunscreen, and/or make‑up after Efudix cream (5‑fluorouracil) has been on long enough to absorb (often around 20 minutes). (7)

What if I can’t tolerate Efudix cream (5‑fluorouracil)?

If Efudix cream (5‑fluorouracil) is too painful or disruptive, contact your doctor early. You may be able to adjust the plan — or switch to options like laser‑assisted photodynamic therapy (PDT) or Aldara cream (imiquimod) depending on your diagnosis. (5, 6, 8)

Your next step

If you’ve been prescribed Efudix cream (5‑fluorouracil) and want help confirming the diagnosis, planning timing/downtime, or comparing alternatives (including laser‑assisted photodynamic therapy (PDT) and Aldara cream (imiquimod)), book a consultation. (1)

References

Book a skin cancer consultation (internal booking page).
Efudix cream (5‑fluorouracil) — patient information / treatment guidance (this page).
Actinic keratosis (solar keratosis) — patient information (internal page).
Squamous cell carcinoma in situ (Bowen’s disease / intraepidermal carcinoma) — patient information (internal page).
Laser‑assisted photodynamic therapy (PDT) for actinic keratosis (solar keratosis) (internal page).
Laser‑assisted photodynamic therapy (PDT) for selected non‑melanoma skin cancers (internal page).
Sunscreen and sun protection — patient guide (internal page).
Aldara cream (imiquimod) — patient guide (internal page).