What is imiquimod, and how does it work?
Imiquimod is a topical immuno-modulator. The cream may work in several different ways, such as recognising abnormal cells and causing inflammation to remove them, but the exact mechanism in which the immune system is activated by imiquimod is not yet known.
In the UK, a 5% imiquimod cream is available (trade name Aldara®).
What skin conditions are treated with imiquimod cream?
Imiquimod cream is licensed for the treatment of sun-damage in the form of superficial pre-cancerous (actinic keratoses), cancerous skin conditions (superficial basal cell carcinoma) and genital viral warts. Imiquimod has been used with some success for many other conditions such as viral warts on non-genital skin, molluscum contagiosum, keloid scarring, different pre-cancerous lesions such as Bowen’s disease, actinic porokeratosis, vulval intra-epithelial neoplasia and lentigo maligna.
Will imiquimod cream cure my skin condition?
Imiquimod cream can cure or improve many skin problems but does not work for everybody. If Imiquimod works for your condition, your skin usually gets worse (red and sore) before it gets better. The redness and soreness settles 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?
How often or for how long you should use imiquimod cream will depend on your skin condition. For actinic keratoses, the licensed usage is for 3 nights a week (e.g. Monday, Wednesday and Friday), but only for 4 weeks with one further course of treatment after one month if necessary. In superficial basal cell carcinoma, the recommended use is Monday to Friday night, with a weekend break, for 6 weeks. In genital warts, imiquimod can be used for up to 16 weeks, on 3 nights a week. Your doctor will discuss a treatment schedule with you.
If you have widespread sun-damage, then the treatment area should be broken up into smaller areas, not using more than one sachet per application (12.5 mg). For example, first complete treatment of the scalp, then treat the face. The more cream is used in any application, the more severe the side effects.
What dose should I take?
You should usually apply Imiquimod cream it 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. Also put some cream on about a centimetre of healthy looking skin around the affected area.
After 20 minutes or so, you may then apply an additional moisturizer. You can also use make-up to cover the redness, but may find this uncomfortable.
In general, you should not cover the treated area with a plaster, unless advised otherwise by your doctor.
You should wash your hands thoroughly after application of the cream.
When should I not apply imiquimod cream?
- Imiquimod cream should not be used on the eyelids, and generally not on the lips, unless specifically prescribed by your doctor for use in that area.
- Do not use imiquimod cream if you are allergic to any of the ingredients.
- Do not apply imiquimod cream if you are pregnant or breastfeeding.
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 may be affected, because it may contain invisibly 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.
With a severe reaction, some patients develop flu-like symptoms such as swollen lymph nodes, aches of the muscles, joints, back or head or mild fever and generally feeling unwell. Taking paracetamol can be helpful.
If the skin or general reaction becomes too severe, it is appropriate to stop the cream for a week or so before restarting it again.
As the abnormal cells die, the skin barrier becomes damaged and therefore susceptible to wound infection. If there is doubt whether you have a normal treatment reaction or a wound infection, please 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 pigmentation may be increased or decreased following severe inflammation. Rarely, this change in pigmentation can be permanent.
Following a severe reaction, there is a small risk of scarring and hair loss.
Imiquimod cream activates the immune system, and very rarely there have been reports of pre-existing auto-immune disease flaring up.
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?