What are the aims of this leaflet?
This leaflet has been written to help you understand more about imiquimod cream. It tells you what it is, how it works, how it is used, and where you can find out more about it.
What is imiquimod, and how does it work?
Imiquimod is a cream that when applied to the skin activates the immune system to recognise abnormal cells and causes inflammation which removes them.
In the UK, two strengths of Imiquimod cream are available, a 5% cream (trade name Aldara®) and a 3.75% cream (Zyclara ®).
What skin conditions are treated with imiquimod cream?
The 5% imiquimod cream is licensed for the treatment of sun damage in the form of superficial pre-cancerous (actinic keratoses) and low grade cancerous skin conditions (superficial basal cell carcinoma). It is also licensed to treat external genital viral warts. The 3.75% cream is licenced for actinic keratoses only. Recent evidence suggests 5% imiquimod may be more effective than other non-surgical treatment options for superficial basal cell carcinoma.
Imiquimod can also be used for other conditions such as nodular basal cell carcinoma, non-genital viral warts, molluscum contagiosum, keloid scarring, melanoma metastases, other pre-cancerous and cancerous lesions such as Bowen disease, actinic porokeratosis, lentigo maligna, cutaneous T-cell lymphoma, vulval intra-epithelial neoplasia and extra-mammary Paget disease. Although imiquimod is sometimes used for these conditions, it is not licenced for them at present.
Will imiquimod cream improve my skin condition?
Imiquimod cream can improve many skin problems and, in some cases, cure the condition, but it does not work for everybody, and the effects may not be permanent. If imiquimod works for your condition, your skin usually gets red and sore before it gets better. The redness and soreness should settle about 2 weeks after stopping the treatment. If used for sun-damage, the skin will eventually appear much smoother. If you have more severe sun-damage, you may require repeated treatment courses in the future to maintain the improvement.
How often should I use imiquimod cream?
You will be advised by your doctor about the number of applications of imiquimod per week and the length of the treatment course as this will vary depending on the skin condition being treated and the strength of cream you are prescribed. Your doctor will discuss a treatment schedule with you.
If you have widespread sun damage, then it is recommended to apply to small areas of the affected zone rather than the whole, usually not using more than one or two sachets per application, depending on which strength of cream is used: for example, first treatment of the scalp, then the face. The more cream is used in any one application, the more severe the side effects may be.
How should I use imiquimod?
You should usually apply imiquimod cream at night and wash it off in the morning. Make sure you always clean your skin prior to the application of the cream. Cut a corner of the sachet and squeeze some cream onto your finger to apply it to the affected area. Allow the cream to go over the edge of the affected area (about 1 cm) onto the surrounding healthy-looking skin.
In general, you should not cover the treated area with a plaster or dressing unless advised otherwise by your doctor.
Do not apply anything else to the skin for at least eight hours after imiquimod application. A bland moisturiser can be used after 8 hours if required to calm the skin but should be washed off before reapplication of imiquimod. Moisturiser can also be used to soothe the skin in the weeks after treatment is complete if needed.
You should wash your hands thoroughly before and immediately after application of the cream.
What cautions apply for use of imiquimod cream?
Imiquimod cream can be used with caution on the eyelids, and the lips, and your doctor will advise about use in that area.
Do not use imiquimod cream if you are allergic to any of the ingredients.
Do not use imiquimod cream if you are pregnant or breastfeeding.
Do not use imiquimod cream if you are spending time in strong sunlight or using sunbeds.
What are the common side effects of imiquimod cream?
Within 3 to 5 days, the skin treated with imiquimod cream can get red and sore. Even normal looking skin around the treated area may be affected, because it may contain invisible abnormal cells. The skin may weep, peel, crack or even blister and then scab over. The area may be itchy or sore, painful and burn. This is caused by the abnormal cells dying and a sign that the treatment is working. The skin reaction tends to be worst in week 2 to 3 of application. For most people, the more sore and red the skin becomes, the better the treatment works. It is normal for redness and some crusting to persist for around 2 weeks after the treatment course has finished.
It may appear that the number of actinic keratoses is increasing early in the treatment period. This is due to the cream causing inflammation and revealing actinic keratoses that were already there but were not visible. These will also get better with the treatment.
Some patients develop flu-like symptoms such as swollen lymph nodes, aches and pains, mild fever and generally feeling unwell. Taking paracetamol can be helpful.
If the skin or general reaction becomes too severe to tolerate, it is helpful to stop the cream for a week or so before restarting it again once the skin is more comfortable.
As the abnormal cells die, the skin barrier becomes damaged and therefore susceptible to wound infection. If you are not sure whether you have a normal treatment reaction or a wound infection, you should see your doctor.
What are the rare side effects of imiquimod cream?
If you have a severe reaction to imiquimod cream, the treated area may become ulcerated. This risk is highest on the legs. The skin colour may become darker or lighter following severe inflammation. Rarely, this change in colour can be permanent. Following a severe reaction, there is a small risk of scarring and hair loss in the treated area. Imiquimod cream activates the immune system, and very rarely there have been reports of pre-existing autoimmune disease flaring up.
Very rarely, a patient can be allergic to Imiquimod cream and develop a severe allergic skin rash.
Where may I find more information on imiquimod cream?
Please note that the BAD provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.
This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.
This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel
BRITISH ASSOCIATION OF DERMATOLOGISTS PATIENT INFORMATION LEAFLET
PRODUCED AUGUST 2011
UPDATED NOVEMBER 2014, FEBRUARY 2018
NEXT REVIEW DATE FEBRUARY 2021