There are different methods to treat actinic keratosis, and each of them has its advantages and disadvantages. The therapy of actinic keratoses is a tailor-made suit for each patient, and the factors that modify the choice of one technique or another are:
· Type, number, and location of lesions to be treated
· Extent of the affected area
· Patient Preferences
· Patient’s personal history
Another fundamental aspect to take into account is that not only the pathology itself must be treated, but it must also be borne in mind that the skin surrounding them is damaged and is more likely to form this type of lesion in the future. Therefore, the optimal treatment is “field” rather than unique and local to the lesion. More information on this aspect of the “cancerization field” can be found here.
What treatments are available for actinic keratosis?
We will divide them into different groups:
1. Physical.
· Cryotherapy. This is the most commonly used therapy. It consists of destroying the lesion by applying liquid nitrogen, which causes a mild burn. Although the percentage of elimination of this pathology is high, it should be remembered that this treatment modality only destroys isolated lesions and has no action on the surrounding skin. After cryotherapy, a blister or scab forms in the treated area and it comes off in a few days. The advantages are its speed and simplicity of application; and the disadvantages are the pain it causes, the formation of scabs and the possibility of causing hypopigmentation (white spot) where it has been used. Cryotherapy can be combined with curettage of the lesion with a teaspoon if desired.
· Electrocoagulation. After the application of local anaesthesia to the lesions, they can be flared with an electrocoagulator, which burns the skin where the tip is located. It is also not a method that acts on the skin surrounding this pathology, and compared to cryotherapy it has the disadvantage of requiring local anaesthesia in each lesion to be removed, as well as a risk of leaving a scar. It is rarely used.
· Surgery. If it is a hypertrophic actinic keratosis or there are doubts as to whether it is already a squamous cell carcinoma, it is advisable to make a complete excision of the lesion and proceed with its histological study.
2. Non-physical.
· 5 fluorouracil (5FU). 5FU is a chemotherapy agent that manages to stop the proliferation of pre-malignant and malignant cells if applied in the form of a cream on actinic keratosis. Its application morning and night allows to progressively eliminate all actinic keratoses and also treat the entire surrounding skin field, achieving the highest rates of effectiveness of all the therapies available today. Despite its excellent efficacy, the skin where there are pre-malignant lesions is irritated during treatment, appearing redness, scaling, crusts and local discomfort. It is common for irritation to appear in areas where there was visibly no lesion but which were in the process of formation: this is the great virtue of 5FU, although it is also its main adverse effect, the intense irritation of the skin beyond the areas with palpable actinic keratosis.
In summary, the advantages of 5FU are:
– Easy application with cream by the patient himself
– Very high efficiency
– Completely treats the entire field of skin cancerization, visible and invisible
– Can reverse signs of skin aging
– It acts preventively against non-visible lesions that are already proliferating
– It is a very economical treatment
On the contrary, the disadvantages are:
– It causes irritation that can be very intense in and around the treated areas
– The treatment can last up to a month
– 5FU cannot be in contact with pregnant women
· Imiquimod. It is a drug applied in cream form that has an immunological mechanism: it stimulates the patient’s immune system to eliminate the malignant and pre-malignant cells of the visible actinic keratoses and the surrounding field of cancer. It has a high efficacy and allows the treatment of lesions that are not yet visible, although it is a costly option and produces irritation that can be very intense and cause fever or flu-like symptoms.
· Diclofenac. It is an anti-inflammatory applied in gel form to the skin. Although its mechanism is unknown, the repetitive application of this preparation on the skin allows visible and incipient actinic keratoses to be eliminated, causing less irritation than other options such as 5FU and imiquimod. However, its effectiveness is not as high and recurrences of lesions are not uncommon after some time after therapy.
· Photodynamic therapy. It consists of the application of a specific cream (5-amino-levulinate) to the area to be treated for 3 hours. This substance penetrates the cells that divide more quickly (such as those of actinic keratosis) and, after being illuminated with a red light lamp in the consultation, allows visible and invisible lesions to be destroyed (cancerization field). It has a high efficiency; it is performed in spaced sessions (it may only require one lesion); it also allows the signs of skin aging to be reversed and the irritation caused is usually not intense. On the contrary, it causes noticeable pain during the session; it can only be practiced in centers with certain facilities and is an expensive treatment for the patient.
Which treatment is best?
The answer to this question depends on the patient’s preferences and the type of lesions. In terms of overall efficacy and complete cure, comparative studies place 5FU as the most effective therapy above the others, although the adverse effects it presents (irritation and crusting) are notable during treatment. If the patient is not willing to spend a few days with scabs and irritation of the treated skin, it is not the ideal therapy for that person; nor is it optimal if the patient has a single lesion. However, it allows visible and invisible lesions to be treated, and reduces the risk of new actinic keratoses appearing in the future. Usually, after treatment, the patient’s satisfaction rate is very high due to the excellent appearance of the skin, although it should be aware that during the treatment period there may be redness and intense scabs.
In reference to the efficacy in terms of complete cure of actinic keratosis, the studies show the following results in descending order: 5 fluorouracil, photodynamic therapy, imiquimod, cryotherapy and diclofenac.
These are the characteristics of the therapeutic options available to treat them:
The following algorithm can be a guide when choosing a therapy depending on the characteristics of this pathology and the patient:
If they are deleted, will they never appear again?
They are the translation of skin sun damage accumulated over years. This sun damage acts on the genetic material of keratinocytes (the cells that make up the outer layer of the skin) and favors mutations and their uncontrolled proliferation. Although treatments for actinic keratoses manage to eliminate the lesions that are present at that time (visible or invisible), they do not guarantee the repair of cellular DNA, so that in the future different actinic keratoses may reappear as a result of these unresolved genetic alterations. This is where the popular concept that “the skin has memory” comes from, and it remembers the Sun accumulated since childhood, even if as adults we are not directly exposed.
So, what is the best treatment for me?
You have to discuss all possible options with your dermatologist and agree on the most effective and comfortable therapeutic method in your case.
REFERENCES
Gupta AK, Paquet M. Network meta-analysis of the outcome “participant complete clearance” in non-immunosuppressed participants of eight interventions for actinic keratosis: a follow-up on a Cochrane review. Br J Dermatol. 2013 Mar 29.