Efudix - 5% Fluorouracil Cream
This is a useful treatment for solar keratoses – also known as actinic keratoses – the scaly, crusty, pinkish areas that result from sun damage.
The cream is applied for about 4 weeks and causes a chemical burn which kills the abnormal cells & results in the skin becoming red, inflamed & tender. Because it penetrates the abnormal skin more readily than healthy skin, often only the solar keratoses themselves will become inflamed. Once the skin has reached an excoriated stage, one stops applying the cream and the healing phase begins.
The main side effects are local irritation, inflammation and itching. Ulceration and crusting may develop. In the long term the treated skin may develop hyper- or hypopigmentation. Telangiectasias (vessel changes), allergic contact dermatitis and photosensitivity may also occur. Management of these effects is usually simple & most people seem to settle without any need for treatment. Cool, wet compresses and bland emollients or moisturiser can bring relief. If very inflamed, a topical steroid - 1% hydrocortisone or a more potent steroid will assist.
When Should I Use Efudix?
Efudix is probably best avoided in the hot summer months as use on already inflamed skin can be difficult. The treated skin can become extremely inflamed and itch and this can be worse in the heat. Using in the cooler months may lessen the risk of post-inflammatory hyperpigmentation. Use on the scalp can occur at any time as patients can wear a hat or cap and this results in less symptoms.
When Shouldn't I Use Efudix?
Efudix should not be used in pregnancy – This is an absolute contraindication and male patients should also avoid getting anyone pregnant while using it.
Efudix treatment Regime?
There are a variety of treatment regimes listed below. Listed in order of recommendation.
For a stoical patient (especially one who has used efudix before) - use it twice a day to all the skin of the face & see the doctor for a review at two weeks. The degree of inflammation will determine how long the treatment needs to be continued. Occasionally, skin can be very inflamed at two weeks and if this is the case, treatment can be stopped at this stage. In most cases, patients need to keep going for the full three weeks and even 4 weeks or more if there is little reaction. Patients should apply the cream to all the affected skin not just the visible keratoses. This allows clinical and sub-clinical lesions to be treated. If patients are concerned by the level of inflammation, the frequency of application can be reduced or stopped altogether. If concerned patients should return for a consultation.
A ‘nervous’ patient or one with a lot of solar keratosis may find ‘pulse therapy’ is a reasonable option. This regime involves applying efudix twice a day two days per week. The other five days are treatment free days. If the skin gets too inflamed, topical steroid ointment on the non-efudix days can be applied. Efudix should be applied on days when there is the least sun exposure - ideally, sun exposure should be avoided altogether. This treatment regime is continued for 6-16 weeks depending on how the patient tolerates the treatment. The clearance rate of this approach may be lower then with the usual ‘twice daily for three weeks’ regime. Generally, patients are reviewed at fortnightly intervals and treatment modified according to response.
Treatment may be commenced with ‘pulse therapy’ and then stepped up at the 2 week review if the patient is coping well and comfortable to increase treatment to the standard regime.
It is important to remember that the greater the inflammatory response the better the therapeutic and cosmetic result.
The Bald Scalp - Efudix is very useful here especially as freezing and photodynamic therapy are often poorly tolerated. Thicker keratoses could be shaved off and the rest softened with a keratolytic like Salicylic Acid 5% before treatment.
The Forearms - Efudix is an option but do not expect the same success as with facial treatment. The treatment may need to be continued for a lot longer duration.
The Lower Lip - Efudix can be used twice daily for 2 weeks & is an alternative to CO2 laser for actinic cheilitis. However, patients find this difficult to tolerate.